SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549
                                 --------------
                                  SCHEDULE 13D
                                 (RULE 13d-101)
             INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT
            TO RULE 13d-1(a) AND AMENDMENTS THERETO FILED PURSUANT TO
                                  RULE 13d-2(a)

                              (Amendment No. 4)(1)


                             Rural/Metro Corporation
                             -----------------------
                                (Name of Issuer)


                          Common Stock, $0.01 Par Value
                          -----------------------------
                         (Title of Class of Securities)


                                    781748108
                                    ---------
                                 (CUSIP Number)

                              STEVEN WOLOSKY, ESQ.
                 OLSHAN GRUNDMAN FROME ROSENZWEIG & WOLOSKY LLP
                                Park Avenue Tower
                               65 East 55th Street
                            New York, New York 10022
                                 (212) 451-2300
                                 --------------
                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)


                                  June 22, 2007
                                  -------------
             (Date of Event Which Requires Filing of This Statement)


      If the filing person has  previously  filed a statement on Schedule 13G to
report the  acquisition  that is the subject of this Schedule 13D, and is filing
this  schedule  because  of Rule  13d-1(e),  13d-1(f)  or  13d-1(g),  check  the
following box /X/.

      NOTE.  Schedules filed in paper format shall include a signed original and
five copies of the schedule,  including  all exhibits.  SEE Rule 13d-7 for other
parties to whom copies are to be sent.

                         (Continued on following pages)
                              (Page 1 of 18 Pages)



--------
(1)   The  remainder  of this cover  page  shall be filled  out for a  reporting
person's  initial  filing on this  form with  respect  to the  subject  class of
securities,  and for any subsequent amendment containing information which would
alter disclosures provided in a prior cover page.

      The information  required on the remainder of this cover page shall not be
deemed to be "filed"  for the purpose of Section 18 of the  Securities  Exchange
Act of 1934 or otherwise  subject to the  liabilities of that section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  SEE the
NOTES).




----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 2 of 18 Pages
----------------------                                    ----------------------


================================================================================
     1         NAME OF REPORTING PERSONS
               I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                    ACCIPITER LIFE SCIENCES FUND, LP
--------------------------------------------------------------------------------
     2         CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*         (a) /X/
                                                                         (b) / /
--------------------------------------------------------------------------------
     3         SEC USE ONLY

--------------------------------------------------------------------------------
     4         SOURCE OF FUNDS*

                    WC
--------------------------------------------------------------------------------
     5         CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
               PURSUANT TO ITEM 2(d) OR 2(e)                                 / /
--------------------------------------------------------------------------------
     6         CITIZENSHIP OR PLACE OF ORGANIZATION

                    DELAWARE
--------------------------------------------------------------------------------
 NUMBER OF         7     SOLE VOTING POWER
   SHARES
BENEFICIALLY                  608,333
  OWNED BY     -----------------------------------------------------------------
    EACH           8     SHARED VOTING POWER
 REPORTING
PERSON WITH                   - 0 -
               -----------------------------------------------------------------
                   9     SOLE DISPOSITIVE POWER

                              608,333
               -----------------------------------------------------------------
                  10     SHARED DISPOSITIVE POWER

                              - 0 -
--------------------------------------------------------------------------------
    11         AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
               PERSON

                    608,333
--------------------------------------------------------------------------------
    12         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
               CERTAIN SHARES*                                               / /
--------------------------------------------------------------------------------
    13         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                    2.5%
--------------------------------------------------------------------------------
    14         TYPE OF REPORTING PERSON*

                    PN
================================================================================

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 3 of 18 Pages
----------------------                                    ----------------------


================================================================================
     1         NAME OF REPORTING PERSONS
               I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                    ACCIPITER LIFE SCIENCES FUND (OFFSHORE), LTD.
--------------------------------------------------------------------------------
     2         CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*         (a) /X/
                                                                         (b) / /
--------------------------------------------------------------------------------
     3         SEC USE ONLY

--------------------------------------------------------------------------------
     4         SOURCE OF FUNDS*

                    WC
--------------------------------------------------------------------------------
     5         CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
               PURSUANT TO ITEM 2(d) OR 2(e)                                 / /
--------------------------------------------------------------------------------
     6         CITIZENSHIP OR PLACE OF ORGANIZATION

                    CAYMAN ISLANDS
--------------------------------------------------------------------------------
 NUMBER OF         7     SOLE VOTING POWER
   SHARES
BENEFICIALLY                  611,213
  OWNED BY     -----------------------------------------------------------------
    EACH           8     SHARED VOTING POWER
 REPORTING
PERSON WITH                   - 0 -
               -----------------------------------------------------------------
                   9     SOLE DISPOSITIVE POWER

                              611,213
               -----------------------------------------------------------------
                  10     SHARED DISPOSITIVE POWER

                              - 0 -
--------------------------------------------------------------------------------
    11         AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
               PERSON

                    611,213
--------------------------------------------------------------------------------
    12         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
               CERTAIN SHARES*                                               / /
--------------------------------------------------------------------------------
    13         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                    2.5%
--------------------------------------------------------------------------------
    14         TYPE OF REPORTING PERSON*

                    CO
================================================================================

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 4 of 18 Pages
----------------------                                    ----------------------


================================================================================
     1         NAME OF REPORTING PERSONS
               I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                    ACCIPITER LIFE SCIENCES FUND II, LP
--------------------------------------------------------------------------------
     2         CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*         (a) /X/
                                                                         (b) / /
--------------------------------------------------------------------------------
     3         SEC USE ONLY

--------------------------------------------------------------------------------
     4         SOURCE OF FUNDS*

                    WC
--------------------------------------------------------------------------------
     5         CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
               PURSUANT TO ITEM 2(d) OR 2(e)                                 / /
--------------------------------------------------------------------------------
     6         CITIZENSHIP OR PLACE OF ORGANIZATION

                    DELAWARE
--------------------------------------------------------------------------------
 NUMBER OF         7     SOLE VOTING POWER
   SHARES
BENEFICIALLY                  467,863
  OWNED BY     -----------------------------------------------------------------
    EACH           8     SHARED VOTING POWER
 REPORTING
PERSON WITH                   - 0 -
               -----------------------------------------------------------------
                   9     SOLE DISPOSITIVE POWER

                              467,863
               -----------------------------------------------------------------
                  10     SHARED DISPOSITIVE POWER

                              - 0 -
--------------------------------------------------------------------------------
    11         AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
               PERSON

                    467,863
--------------------------------------------------------------------------------
    12         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
               CERTAIN SHARES*                                               / /
--------------------------------------------------------------------------------
    13         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                    1.9%
--------------------------------------------------------------------------------
    14         TYPE OF REPORTING PERSON*

                    PN
================================================================================

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 5 of 18 Pages
----------------------                                    ----------------------


================================================================================
     1         NAME OF REPORTING PERSONS
               I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                    ACCIPITER LIFE SCIENCES FUND II (OFFSHORE), LTD.
--------------------------------------------------------------------------------
     2         CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*         (a) /X/
                                                                         (b) / /
--------------------------------------------------------------------------------
     3         SEC USE ONLY

--------------------------------------------------------------------------------
     4         SOURCE OF FUNDS*

                    WC
--------------------------------------------------------------------------------
     5         CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
               PURSUANT TO ITEM 2(d) OR 2(e)                                 / /
--------------------------------------------------------------------------------
     6         CITIZENSHIP OR PLACE OF ORGANIZATION

                    CAYMAN ISLAND
--------------------------------------------------------------------------------
 NUMBER OF         7     SOLE VOTING POWER
   SHARES
BENEFICIALLY                  958,853
  OWNED BY     -----------------------------------------------------------------
    EACH           8     SHARED VOTING POWER
 REPORTING
PERSON WITH                   - 0 -
               -----------------------------------------------------------------
                   9     SOLE DISPOSITIVE POWER

                              958,853
               -----------------------------------------------------------------
                  10     SHARED DISPOSITIVE POWER

                              - 0 -
--------------------------------------------------------------------------------
    11         AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
               PERSON

                    958,853
--------------------------------------------------------------------------------
    12         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
               CERTAIN SHARES*                                               / /
--------------------------------------------------------------------------------
    13         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                    3.9%
--------------------------------------------------------------------------------
    14         TYPE OF REPORTING PERSON*

                    CO
================================================================================

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 6 of 18 Pages
----------------------                                    ----------------------


================================================================================
     1         NAME OF REPORTING PERSONS
               I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                    ACCIPITER LIFE SCIENCES FUND II (QP), LP
--------------------------------------------------------------------------------
     2         CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*         (a) /X/
                                                                         (b) / /
--------------------------------------------------------------------------------
     3         SEC USE ONLY

--------------------------------------------------------------------------------
     4         SOURCE OF FUNDS*

                    WC
--------------------------------------------------------------------------------
     5         CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
               PURSUANT TO ITEM 2(d) OR 2(e)                                 / /
--------------------------------------------------------------------------------
     6         CITIZENSHIP OR PLACE OF ORGANIZATION

                    DELAWARE
--------------------------------------------------------------------------------
 NUMBER OF         7     SOLE VOTING POWER
   SHARES
BENEFICIALLY                  556,936
  OWNED BY     -----------------------------------------------------------------
    EACH           8     SHARED VOTING POWER
 REPORTING
PERSON WITH                   - 0 -
               -----------------------------------------------------------------
                   9     SOLE DISPOSITIVE POWER

                              556,936
               -----------------------------------------------------------------
                  10     SHARED DISPOSITIVE POWER

                              - 0 -
--------------------------------------------------------------------------------
    11         AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
               PERSON

                    556,936
--------------------------------------------------------------------------------
    12         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
               CERTAIN SHARES*                                               / /
--------------------------------------------------------------------------------
    13         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                    2.3%
--------------------------------------------------------------------------------
    14         TYPE OF REPORTING PERSON*

                    PN
================================================================================

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 7 of 18 Pages
----------------------                                    ----------------------


================================================================================
     1         NAME OF REPORTING PERSONS
               I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                    CANDENS CAPITAL, LLC
--------------------------------------------------------------------------------
     2         CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*         (a) /X/
                                                                         (b) / /
--------------------------------------------------------------------------------
     3         SEC USE ONLY

--------------------------------------------------------------------------------
     4         SOURCE OF FUNDS*

                    AF
--------------------------------------------------------------------------------
     5         CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
               PURSUANT TO ITEM 2(d) OR 2(e)                                 / /
--------------------------------------------------------------------------------
     6         CITIZENSHIP OR PLACE OF ORGANIZATION

                    DELAWARE
--------------------------------------------------------------------------------
 NUMBER OF         7     SOLE VOTING POWER
   SHARES
BENEFICIALLY                  1,633,132
  OWNED BY     -----------------------------------------------------------------
    EACH           8     SHARED VOTING POWER
 REPORTING
PERSON WITH                   - 0 -
               -----------------------------------------------------------------
                   9     SOLE DISPOSITIVE POWER

                              1,633,132
               -----------------------------------------------------------------
                  10     SHARED DISPOSITIVE POWER

                              - 0 -
--------------------------------------------------------------------------------
    11         AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
               PERSON

                    1,633,132
--------------------------------------------------------------------------------
    12         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
               CERTAIN SHARES*                                               / /
--------------------------------------------------------------------------------
    13         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                    6.6%
--------------------------------------------------------------------------------
    14         TYPE OF REPORTING PERSON*

                    OO
================================================================================

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 8 of 18 Pages
----------------------                                    ----------------------


================================================================================
     1         NAME OF REPORTING PERSONS
               I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                    ACCIPITER CAPITAL MANAGEMENT, LLC
--------------------------------------------------------------------------------
     2         CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*         (a) /X/
                                                                         (b) / /
--------------------------------------------------------------------------------
     3         SEC USE ONLY

--------------------------------------------------------------------------------
     4         SOURCE OF FUNDS*

                    AF
--------------------------------------------------------------------------------
     5         CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
               PURSUANT TO ITEM 2(d) OR 2(e)                                 / /
--------------------------------------------------------------------------------
     6         CITIZENSHIP OR PLACE OF ORGANIZATION

                    DELAWARE
--------------------------------------------------------------------------------
 NUMBER OF         7     SOLE VOTING POWER
   SHARES
BENEFICIALLY                  1,570,066
  OWNED BY     -----------------------------------------------------------------
    EACH           8     SHARED VOTING POWER
 REPORTING
PERSON WITH                   - 0 -
               -----------------------------------------------------------------
                   9     SOLE DISPOSITIVE POWER

                              1,570,066
               -----------------------------------------------------------------
                  10     SHARED DISPOSITIVE POWER

                              - 0 -
--------------------------------------------------------------------------------
    11         AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
               PERSON

                    1,570,066
--------------------------------------------------------------------------------
    12         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
               CERTAIN SHARES*                                               / /
--------------------------------------------------------------------------------
    13         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                    6.4%
--------------------------------------------------------------------------------
    14         TYPE OF REPORTING PERSON*

                    OO
================================================================================

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 9 of 18 Pages
----------------------                                    ----------------------


================================================================================
     1         NAME OF REPORTING PERSONS
               I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY)

                    GABE HOFFMAN
--------------------------------------------------------------------------------
     2         CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*         (a) /X/
                                                                         (b) / /
--------------------------------------------------------------------------------
     3         SEC USE ONLY

--------------------------------------------------------------------------------
     4         SOURCE OF FUNDS*

                    AF
--------------------------------------------------------------------------------
     5         CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED
               PURSUANT TO ITEM 2(d) OR 2(e)                                 / /
--------------------------------------------------------------------------------
     6         CITIZENSHIP OR PLACE OF ORGANIZATION

                    USA
--------------------------------------------------------------------------------
 NUMBER OF         7     SOLE VOTING POWER
   SHARES
BENEFICIALLY                  3,203,198
  OWNED BY     -----------------------------------------------------------------
    EACH           8     SHARED VOTING POWER
 REPORTING
PERSON WITH                   - 0 -
               -----------------------------------------------------------------
                   9     SOLE DISPOSITIVE POWER

                              3,203,198
               -----------------------------------------------------------------
                  10     SHARED DISPOSITIVE POWER

                              - 0 -
--------------------------------------------------------------------------------
    11         AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING
               PERSON

                    3,203,198
--------------------------------------------------------------------------------
    12         CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
               CERTAIN SHARES*                                               / /
--------------------------------------------------------------------------------
    13         PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11)

                    12.98%
--------------------------------------------------------------------------------
    14         TYPE OF REPORTING PERSON*

                    IN
================================================================================

                      *SEE INSTRUCTIONS BEFORE FILLING OUT!



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 10 of 18 Pages
----------------------                                    ----------------------


      The following  constitutes  Amendment  No. 4 ("Amendment  No. 4") to the
Schedule  13D  filed by the  undersigned.  This  Amendment  No. 4  amends  the
Schedule 13D as specifically set forth.

      Item 3 is hereby amended and restated to read as follows:

Item 3.     SOURCE AND AMOUNT OF FUNDS OR OTHER CONSIDERATION.

            The aggregate purchase price of the 608,333 Shares owned by ALS Fund
is $4,547,234 including brokerage commissions. The Shares owned by ALS Fund were
acquired with partnership funds.

            The aggregate purchase price of the 467,863 Shares owned by ALS Fund
II is $3,663,121,  including brokerage commissions. The Shares owned by ALS Fund
II were acquired with partnership funds.

            The aggregate purchase price of the 556,936 Shares owned by ALS Fund
II QP is $4,271,375,  including brokerage  commissions.  The Shares owned by ALS
Fund II QP were acquired with partnership funds.

            The aggregate purchase price of the 611,213 Shares owned by ALS Fund
Offshore is $4,548,866, including brokerage commissions. The Shares owned by ALS
Fund Offshore were acquired using its working capital.

            The aggregate purchase price of the 958,853 Shares owned by ALS Fund
II Offshore is $7,312,541,  including brokerage commissions. The Shares owned by
ALS Fund II Offshore were acquired using its working capital.

      Item 5(a) is hereby amended and restated to read as follows:

            (a) The aggregate percentage of Shares reported owned by each person
named herein is based upon  24,679,103  Shares  outstanding,  which is the total
number  of Shares  outstanding  as of May 7, 2007 as  reported  in the  Issuer's
Quarterly  Report  on Form  10-Q as  filed  with  the  Securities  and  Exchange
Commission on May 10, 2007.

      As of the close of business on June 25,  2007,  ALS Fund,  ALS Fund II and
ALS Fund II QP  beneficially  owned 608,333  Shares,  467,863 Shares and 556,936
Shares,  respectively,  constituting  approximately  2.5%,  1.9% and 2.3% of the
Shares  outstanding,  respectively.  As the general partner of each of ALS Fund,
ALS Fund II and ALS Fund II QP,  Candens  Capital may be deemed to  beneficially
own the 1,633,132  Shares  collectively  owned by ALS Fund,  ALS Fund II and ALS
Fund II QP, constituting approximately 6.6% of the Shares outstanding.

      As of the close of business on June 25,  2007,  ALS Fund  Offshore and ALS
Fund  II  Offshore   beneficially  owned  611,213  Shares  and  958,853  Shares,
respectively,   constituting   approximately   2.5%  and  3.9%  of  the   Shares
outstanding,  respectively.  As the  investment  manager  of  each  of ALS  Fund
Offshore  and ALS  Fund II  Offshore,  Accipiter  Management  may be  deemed  to
beneficially  own the 1,570,066 Shares  collectively  owned by ALS Fund Offshore
and  ALS  Fund  II  Offshore,  constituting  approximately  6.4%  of the  Shares
outstanding.



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 11 of 18 Pages
----------------------                                    ----------------------


      As the  managing  member  of  each of  Accipiter  Management  and  Candens
Capital,  Mr.  Hoffman  may be  deemed  to  beneficially  own  3,203,198  Shares
collectively owned by the Accipiter Entities,  constituting approximately 12.98%
of the Shares  outstanding.  Mr. Hoffman has sole voting and  dispositive  power
with respect to the 3,203,198  Shares owned by the Accipiter  Entities by virtue
of his authority to vote and dispose of such Shares.

      Item 5(c) is hereby amended to add the following:

            (c)  Schedule  A  annexed  hereto  lists  all  transactions  by  the
Reporting  Persons in the Issuer's  securities  within the last 60 days.  All of
such transactions were effected in the open market.

      Item 6 is hereby amended to add the following:

      On June 26,  2007,  Accipiter  Life  Sciences  Fund,  LP,  Accipiter  Life
Sciences Fund II, LP,  Accipiter Life Sciences Fund II (QP), LP,  Accipiter Life
Sciences Fund  (Offshore),  Ltd.,  Accipiter  Life Sciences Fund II  (Offshore),
Ltd.,  Accipiter Capital Management,  LLC, Candens Capital, LLC and Gabe Hoffman
(collectively,  the "Group")  entered into a Joint Filing  Agreement (the "Joint
Filing  Agreement") in which the parties agreed to the joint filing on behalf of
each of them of statements on Schedule 13D with respect to the securities of the
Issuer to the extent required by applicable  law. The Joint Filing  Agreement is
attached as Exhibit 3 hereto and is incorporated herein by reference.

      Item 7 is hereby amended to add the following exhibit:

            3.    Joint Filing  Agreement by and among  Accipiter  Life Sciences
                  Fund, LP,  Accipiter Life Sciences Fund II, LP, Accipiter Life
                  Sciences  Fund II  (QP),  LP,  Accipiter  Life  Sciences  Fund
                  (Offshore),  Ltd., Accipiter Life Sciences Fund II (Offshore),
                  Ltd., Accipiter Capital Management,  LLC, Candens Capital, LLC
                  and Gabe Hoffman, dated June 26, 2007.



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 12 of 18 Pages
----------------------                                    ----------------------


                                   SIGNATURES

            After  reasonable  inquiry  and to the  best  of his  knowledge  and
belief, each of the undersigned certifies that the information set forth in this
statement is true, complete and correct.

Dated: June 26, 2007                     ACCIPITER LIFE SCIENCES FUND, LP

                                         By: Candens Capital, LLC
                                             its general partner

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         ACCIPITER LIFE SCIENCES FUND II, LP

                                         By: Candens Capital, LLC
                                             its general partner

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         ACCIPITER LIFE SCIENCES FUND II (QP),
                                         LP

                                         By: Candens Capital, LLC
                                             its general partner

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         ACCIPITER LIFE SCIENCES FUND
                                         (OFFSHORE), LTD.

                                         By: Accipiter Capital Management, LLC
                                             its investment manager

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         ACCIPITER LIFE SCIENCES FUND II
                                         (OFFSHORE), LTD.

                                         By: Accipiter Capital Management, LLC
                                             its investment manager

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member




----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 13 of 18 Pages
----------------------                                    ----------------------


                                         ACCIPITER CAPITAL MANAGEMENT, LLC

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         CANDENS CAPITAL, LLC

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         /s/ Gabe Hoffman
                                         ---------------------------------------
                                         GABE HOFFMAN



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 14 of 18 Pages
----------------------                                    ----------------------


                                   SCHEDULE A

                      TRANSACTIONS IN SHARES OF THE ISSUER
                             WITHIN THE LAST 60 DAYS


              ALL PURCHASES AND SALES WERE MADE IN THE OPEN MARKET.


          Class                  Quantity      Price Per        Date of
       of Security              Purchased       Unit ($)        Purchase


      I. ACCIPITER LIFE SCIENCES FUND, LP

      Common Stock                 17,913        6.1550         06/22/07
      Common Stock                  9,096        6.2953         06/22/07
      Common Stock                 17,913        6.1550         06/22/07
      Common Stock                119,875        6.1550         06/22/07

      II. AFFILIATES OF ACCIPITER LIFE SCIENCES FUND, LP


      ACCIPITER LIFE SCIENCES FUND II, LP
      Common Stock                  9,366        6.1550         06/22/07
      Common Stock                  4,756        6.2953         06/22/07
      Common Stock                  9,367        6.1550         06/22/07
      Common Stock                 62,683        6.1550         06/22/07


      ACCIPITER LIFE SCIENCES FUND (OFFSHORE), LTD.
      Common Stock                 17,957        6.1550         06/22/07
      Common Stock                  9,118        6.2953         06/22/07
      Common Stock                 17,957        6.1550         06/22/07
      Common Stock                120,171        6.1550         06/22/07


      ACCIPITER LIFE SCIENCES FUND II (OFFSHORE), LTD.
      Common Stock                 18,613        6.1550         06/22/07
      Common Stock                  9,452        6.2953         06/22/07
      Common Stock                 18,612        6.1550         06/22/07
      Common Stock                124,563        6.1550         06/22/07



----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 15 of 18 Pages
----------------------                                    ----------------------


      ACCIPITER LIFE SCIENCES FUND II (QP), LP
      Common Stock                 11,151        6.1550         06/22/07
      Common Stock                  5,662        6.2953         06/22/07
      Common Stock                 11,151        6.1550         06/22/07
      Common Stock                 74,624        6.1550         06/22/07


                        ACCIPITER CAPITAL MANAGEMENT, LLC

                                      NONE

                              CANDENS CAPITAL, LLC

                                      NONE

                                  GABE HOFFMAN

                                      NONE




----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 16 of 18 Pages
----------------------                                    ----------------------


EXHIBIT INDEX

            Exhibit                                                Page
            -------                                                ----

3.    Joint Filing Agreement by and among Accipiter Life         17 to 18
      Sciences Fund, LP, Accipiter Life Sciences Fund
      II, LP, Accipiter Life Sciences Fund II (QP), LP,
      Accipiter Life Sciences Fund (Offshore), Ltd.,
      Accipiter Life Sciences Fund II (Offshore), Ltd.,
      Accipiter Capital Management, LLC, Candens
      Capital, LLC and Gabe Hoffman, dated June 26, 2007.




----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 17 of 18 Pages
----------------------                                    ----------------------


                             JOINT FILING AGREEMENT

      In accordance with Rule 13d-1(k)(1)(iii) under the Securities Exchange Act
of 1934, as amended, the persons named below agree to the joint filing on behalf
of each of them of this  Amendment No. 4 to Schedule 13D  (including  subsequent
amendments thereto) with respect to the Common Stock of Rural/Metro Corporation.
This Joint Filing Agreement shall be filed as an Exhibit to such Statement.

      Dated: June 26, 2007

                                         ACCIPITER LIFE SCIENCES FUND, LP

                                         By: Candens Capital, LLC
                                             its general partner

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         ACCIPITER LIFE SCIENCES FUND II, LP

                                         By: Candens Capital, LLC
                                             its general partner

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         ACCIPITER LIFE SCIENCES FUND II (QP),
                                         LP

                                         By: Candens Capital, LLC
                                             its general partner

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         ACCIPITER LIFE SCIENCES FUND
                                         (OFFSHORE), LTD.

                                         By: Accipiter Capital Management, LLC
                                             its investment manager

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


----------------------                                    ----------------------
CUSIP No. 781748108                   13D                    Page 18 of 18 Pages
----------------------                                    ----------------------


                                         ACCIPITER LIFE SCIENCES FUND II
                                         (OFFSHORE), LTD.

                                         By: Accipiter Capital Management, LLC
                                             its investment manager

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         ACCIPITER CAPITAL MANAGEMENT, LLC

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         CANDENS CAPITAL, LLC

                                         By: /s/ Gabe Hoffman
                                             ----------------------------------
                                             Gabe Hoffman, Managing Member


                                         /s/ Gabe Hoffman
                                         ---------------------------------------
                                         GABE HOFFMAN