Exhibit 99

[ESSI logo]                                                          RELEASE
                    --------------------------------------------------------
                                 201 Evans Lane  o  St. Louis, MO 63121-1126


For more information, contact:                                April 14, 2005
Larry Cox, Communications Mgr
314/553-4960, lcox@essihq.com



                         ENGINEERED SUPPORT SYSTEMS
                      TO ACQUIRE MOBILIZED SYSTEMS INC.

ST. LOUIS, MO--ENGINEERED SUPPORT SYSTEMS, INC. (Nasdaq: EASI ) has agreed
to acquire Mobilized Systems, Inc. (MSI), an industry leader in the design,
manufacture and testing of highly specialized trailers, shelters and
environmental control systems primarily for the defense industry. The
all-cash deal involves the purchase of the outstanding equity of MSI. Terms
of the pending transaction were not disclosed. The Company will fund the
transaction with available cash resources and/or borrowings under its
unsecured credit facility. The acquisition of MSI will be immediately
accretive to earnings, according to Gerald A. Potthoff, Vice Chairman and
CEO of Engineered Support Systems.

The mobile systems manufactured by MSI play a critical role in providing
environmentally-controlled, enclosures for personnel as well as sensitive
military electronics, communications and simulation/training systems. MSI is
particularly well-positioned to capitalize on the dynamic opportunities
inherent in the market for mobile military shelters based on its diverse
project experience in radar system shelters, mobile firearms training,
missile transporters, simulators, warfare training and secure communications
systems.

MSI's 150 employees operate from office/manufacturing facilities
encompassing 110,000 square feet in Cincinnati, Ohio, directly adjacent to
those of Engineered Support Systems' wholly-owned subsidiary Engineered
Environments, Inc. (EEi), acquired in 2003. MSI will be integrated into the
Company's Support Systems Group. For calendar 2004, the privately-held MSI
posted revenues of approximately $23 million. MSI's primary customers
include many of the larger defense primes such as Raytheon, Lockheed Martin,
Boeing and others.

"MSI has been repeatedly recognized by major defense contractors as a top
provider of highly-specialized, customized mobile enclosure solutions for
complex applications and system requirements," Potthoff said. "MSI's strong
engineering talent enables it to meet customers' increasingly demanding
requirements," requirements that include EMI shielding, environmental
control, acoustics and shock absorption, he explained. He added that
increased emphasis in the defense community on mobile training, warfare
simulation and secure communications systems is fueling robust demand for
MSI's capabilities.

                                  - MORE -

PROVIDING ADVANCED SUSTAINMENT SOLUTIONS TO THOSE WHO SERVE IN A CHANGING WORLD
- -------------------------------------------------------------------------------


MSI 2-2-2

"With MSI's close proximity and similar market focus with Engineered
Environments, we believe tremendous operational and business development
synergies exist between the two organizations, Potthoff said. "Both firms
will pursue strategic growth opportunities for defense and related
industrial applications requiring customized mobile enclosure solutions. And
adding MSI helps us leverage many of our long-standing working relationships
with the major defense primes -- a key market focus area for our Company.

"We welcome the MSI employees, especially their four operator-shareholders,
to the Engineered Support Systems team and look forward to great success
going forward," he said.

Engineered Support Systems, Inc. provides advanced sustainment solutions
including the design, manufacture and supply of integrated military
electronics, support equipment and technical and logistics services for all
branches of America's armed forces and certain foreign militaries, homeland
security forces and selected government and intelligence agencies. The
company also produces specialized equipment and systems for commercial and
industrial applications. For additional information, please visit the
Company's website at http://www.engineeredsupport.com.

Certain statements in this press release are forward looking in nature and,
accordingly, are subject to risks and uncertainties. The actual results may
differ materially from those described or contemplated.

                                   * * * *



PROVIDING ADVANCED SUSTAINMENT SOLUTIONS TO THOSE WHO SERVE IN A CHANGING WORLD
- -------------------------------------------------------------------------------