FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * Devine John   2. Issuer Name and Ticker or Trading Symbol SOTERA DEFENSE SOLUTIONS, INC. [GTEC] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 1501 FARM CREDIT DRIVE, SUITE 2300 3. Date of Earliest Transaction (Month/Day/Year) 04/04/2011 (Street) MCLEAN, VA 22102-5011 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 04/04/2011   U   5,556 (1) D $ 24.25 5,564 D   Common Stock 04/04/2011   D   5,564 (2) D $ 24.25 0 D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Common Stock Option (Right to Buy)

$ 6.52

04/04/2011

D

5,009

(3)

01/01/2018

Common Stock

5,009

$ 17.73

0

D

Common Stock Option (Right to Buy)

$ 13.48

04/04/2011

D

10,000

(4)

02/26/2020

Common Stock

10,000

$ 10.77

0

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Devine John 1501 FARM CREDIT DRIVE SUITE 2300 MCLEAN, VA 22102-5011	X

Signatures

/s/ Lisa Broome, Attorney-in-Fact for John Devine		04/04/2011
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Represents shares tendered to Sentinel Acquisition Corporation ("Sentinel") pursuant to the Offer to Purchase, dated March 7, 2011.
(2)	Represents unvested restricted shares held by the Reporting Person. Pursuant to the Agreement and Plan of Merger, dated March 2, 2011, between Global Defense Technology & Systems, Inc., Sentinel, and Sentinel Acquisition Holdings Inc. (the "Merger Agreement"), these shares were canceled in exchange for a cash payment of $24.25 per share.
(3)	Under the Merger Agreement, this option, which provided for vesting in four equal annual installments beginning January 1, 2009, was canceled in exchange for a cash payment representing the difference between $24.25 per share and the exercise price of the option.
(4)	Under the Merger Agreement, this option, which provided for vesting in four equal annual installments beginning February 26, 2011, was canceled in exchange for a cash payment representing the difference between $24.25 per share and the exercise price of the option.

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