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                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549
 
                         Commission File number 0-19152
 
                       AUTOMATED SECURITY (HOLDINGS) PLC
                               ENGLAND AND WALES
                (Jurisdiction of incorporation of organization)
            The Clock House, The Campus, Spring Way Hemel Hempstead,
                         Hertfordshire HP2 7TL England
                         (Address of principal offices)
                                    FORM 6-K
                        REPORT OF FOREIGN PRIVATE ISSUER
                      PURSUANT TO RULE 13a-16 OR 15d-16 OF
                      THE SECURITIES EXCHANGE ACT OF 1934
 
    (Indicate by check mark whether the registrant files or will file annual
reports under cover of Form 20-F or Form 40-F.)
 
    Form 20-F /X/    Form 40-F / /
 
    (Indicate by check mark whether the registrant by furnishing the information
contained in this form is also thereby furnishing the information to the
Commission pursuant to Rule 12g3-2(b) under the Securities Exchange Act of
1934.)
 
    Yes / /    No /X/
 
    (If "Yes" is marked, indicate below the file number assigned to the
registrant in connection with Rule 12g3-2(b): 82-     .)
 
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                                                                          [LOGO]
 
FOR IMMEDIATE RELEASE
 
                                  Contact: Peter Bertram
                                         Automated Security (Holdings) PLC
                                         011-441-44-260-008
                                                   -or-
                                         Brian Rafferty
                                         Taylor Rafferty Associates
                                         212-889-4350
 
PROPOSED ACQUISITION OF AUTOMATED SECURITY (HOLDINGS) PLC ("ASH") BY ADT LIMITED
("ADT"): RESULT OF COURT MEETINGS
 
    London, August 22, 1996 -- Automated Security (Holdings) PLC (ASH) (NYSE:
ASI), a leading international electronic security systems group, today announced
that its board, which has been advised by Charterhouse Bank Limited and Smith
Barney Inc., announces that the Court Meetings convened to consider the scheme
of arrangement to effect the acquisition of ASH by ADT ("the Scheme") were held
today in accordance with the notices of those meetings set out in the circular
to shareholders dated July 22, 1996. The resolutions to approve the Scheme were
duly passed.
 
    - A majority in number of the holders of Ordinary Shares present and voting
      either in person or by proxy, representing 67,668,936 Ordinary Shares
      (98.65% of the Ordinary Shares voted at the meeting), voted in favor of
      the Scheme.
 
    - A majority in number of the holders of 5% Preference Shares present and
      voting either in person or by proxy, representing 4,920,094 5% Preference
      Shares (99.95% of the 5% Preference Shares voted at the meeting), voted in
      favor of the Scheme.
 
    - A majority in number of the holders of 6% Preference Shares present and
      voting either in person or by proxy, representing 18,524,093 6% Preference
      Shares (99.96% of the 6% Preference Shares voted at the meeting), voted in
      favor of the Scheme.
 
    Subject to the sanction of the Court and the satisfaction or waiver of the
other remaining conditions, it is expected that the Scheme will become effective
on September 5, 1996 and that trading in the new ADT common shares to be issued
as consideration will commence on September 6, 1996.
 
    With operations in the UK and US, ASH is a leading provider of security
systems for the commercial, industrial, and residential markets.
 
    In addition to the ADRs listed on the NYSE (each equal to two ordinary
shares), ASH's ordinary shares are traded on the London Stock Exchange and
prices may be accessed on the Reuter Equities 2000 Service under the symbol
ATOS.L and on Quotron under the symbol ATOSU.EU.

                                   SIGNATURES
 
    Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned, thereunto duly authorized.
 
                                          Automated Security (Holdings) PLC
 
                                          By:          /s/ PETER BERTRAM
 
                                             -----------------------------------
                                              Peter Bertram
                                             Chief Financial Officer
 
Date of signing: August 26, 1996