Exhibit 99.1


FOR IMMEDIATE RELEASE                 CONTACT:             Leonard E. Moodispaw
                                                           CEO & President
                                                           301.939.7000

               ESSEX AGREES TO ACQUIRE COGNITIVE COMPUTING COMPANY

COLUMBIA, MD - April 21, 2004 - Essex Corporation (NASDAQ: KEYW), announces that
it has entered into an exclusive  Letter of Intent to acquire  Computer  Science
Innovations  (CSI) of Melbourne,  Florida.  The  acquisition  will be subject to
customary  closing  conditions  and is expected to close within the next several
weeks. CSI is a profitable,  employee-owned company with 35 employees and annual
revenue  of  approximately  $7.5  million,   focused  on  cognitive   processing
technology. CSI has proprietary techniques,  algorithms, and tools that are used
to build custom "cognitive engines" for a broad range of intelligence,  defense,
and commercial customers and applications.

"CSI is an  excellent  fit to our  acquisition  strategy,"  according to Leonard
Moodispaw,  CEO & President of Essex Corporation.  "CSI is a sound business that
brings new and highly complementary technologies,  capabilities and customers to
Essex."

"Coupling  the  Essex  optical   processing   technology  with  CSI's  cognitive
processing  algorithms  offers the  possibility of breaking  through  processing
barriers that have limited the  intelligence  and  effectiveness  of computers,"
according to Arthur Money,  former  Assistant  Secretary of Defense for Command,
Control, Communications, and Intelligence (C3I) and a member of Essex's Board of
Directors.  "This is an  exciting  combination  that has both near term and long
term value in tackling the extreme  information  challenges  facing our Nation's
intelligence and defense communities."

The Defense Advanced  Research  Projects Agency (DARPA)  announced in March 2004
that  Cognitive  Computing is one of its eight  strategic  thrusts.  Examples of
cognitive applications include:  helping intelligence analysts identify critical
new  information,  capturing and organizing  unstructured  text, and intelligent
searching of the Internet.

Mr. James Devine,  Executive Vice  President and General  Manager at Essex adds,
"There are four main elements of CSI's technology and capabilities:  data mining
and information extraction;  natural language processing; machine reasoning; and
data fusion. These are the next generation of tools needed to solve intelligence
and homeland security information  problems. We have already started integrating
these tools to expand our solutions  offerings to our existing  customers and to
reach out to new  customers  in  homeland  security  and other  rapidly  growing
markets."


                                   - M O R E -




ESSEX AGREES TO ACQUIRE COGNITIVE
COMPUTING COMPANY
PAGE 2 OF 2


ABOUT ESSEX:  Essex creates solutions for today's most advanced signal and image
processing challenges,  serving commercial,  defense and intelligence customers.
For more information contact Essex Corporation,  9150 Guilford Road, Columbia MD
21046; Phone 301.939.7000;  Fax 301.953.7880;  E-mail info@essexcorp.com,  or on
the Web at WWW.ESSEXCORP.COM.

THIS PRESS RELEASE MAY CONTAIN  "FORWARD-LOOKING  STATEMENTS" WITHIN THE MEANING
OF THE UNITED STATES PRIVATE SECURITIES REFORM ACT OF 1995. THESE STATEMENTS ARE
BASED ON MANAGEMENT'S CURRENT EXPECTATIONS AND ARE SUBJECT TO RISKS, UNCERTAINTY
AND CHANGES IN  CIRCUMSTANCES,  WHICH MAY CAUSE ACTUAL  RESULTS,  PERFORMANCE OR
ACHIEVEMENTS  TO DIFFER  MATERIALLY  FROM  ANTICIPATED  RESULTS,  PERFORMANCE OR
ACHIEVEMENTS. ALL STATEMENTS CONTAINED HEREIN THAT ARE NOT CLEARLY HISTORICAL IN
NATURE ARE FORWARD  LOOKING.  THE  FORWARD-LOOKING  STATEMENTS  IN THIS  RELEASE
INCLUDE STATEMENTS ADDRESSING THE FOLLOWING SUBJECTS: FUTURE FINANCIAL CONDITION
AND OPERATING RESULTS. ECONOMIC, BUSINESS, COMPETITIVE AND/OR REGULATORY FACTORS
AFFECTING ESSEX'S BUSINESSES ARE EXAMPLES OF FACTORS,  AMONG OTHERS,  THAT COULD
CAUSE  ACTUAL  RESULTS  TO  DIFFER   MATERIALLY  FROM  THOSE  DESCRIBED  IN  THE
FORWARD-LOOKING STATEMENTS.

MORE DETAILED  INFORMATION ABOUT THESE AND OTHER FACTORS IS SET FORTH IN ESSEX'S
ANNUAL REPORT ON FORM 10-K FOR THE FISCAL YEAR ENDED DECEMBER 28, 2003. ESSEX IS
UNDER NO OBLIGATION TO (AND EXPRESSLY  DISCLAIMS ANY SUCH  OBLIGATION TO) UPDATE
OR ALTER ITS FORWARD-LOOKING  STATEMENTS WHETHER AS A RESULT OF NEW INFORMATION,
FUTURE EVENTS OR OTHERWISE.


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