WAIVER AND FOURTH AMENDMENT TO CREDIT AGREEMENT

Exhibit 10.2

WAIVER AND FOURTH AMENDMENT TO CREDIT AGREEMENT

This WAIVER AND FOURTH AMENDMENT TO CREDIT AGREEMENT (this “Amendment”) is made on May 10, 2007, among DEVCON SECURITY HOLDINGS, INC., a Florida corporation (“Holdings”), DEVCON SECURITY SERVICES CORP., a Delaware Corporation (“Services”), MUTUAL CENTRAL ALARM SERVICES INC., a New York corporation (“Mutual”), STAT-LAND BURGLAR ALARM SYSTEMS & DEVICES INC., a New York corporation (“Stat-Land”, together with Holdings, Services, and Mutual, are hereinafter referred to individually as a “Borrower” and collectively as “Borrowers”), and CAPITALSOURCE FINANCE LLC, as Agent (in such capacity, the “Agent”), for the Lenders parties thereto and as a Lender. All capitalized terms used but not defined herein shall have the respective meanings ascribed to such terms in the Credit Agreement described below.

W I T N E S S E T H:

A. Borrowers, Agent and Lenders have entered into that certain Credit Agreement dated as of November 10, 2005, as modified by that certain First Amendment to Credit Agreement, Master Reaffirmation and Joinder to Loan Documents, dated March 6, 2006, that certain Second Amendment to Credit Agreement dated as of April 11, 2006 and that certain Waiver and Third Amendment to Credit Agreement dated December 29, 2006 (as amended hereby and as may from time to time be further amended, restated, supplemented or otherwise modified, the “Credit Agreement”), pursuant to which Agent and Lenders made Loans and other financial accommodations to Borrowers, subject to the terms and conditions set forth in the Credit Agreement, and have entered into the other Loan Documents.

B. Borrowers are not in compliance with the provisions of the Credit Agreement as a result of their failure to maintain the required Fixed Charge Coverage Ratio for the periods ended March 31, 2007 and April 30, 2007 (collectively, the “Noncompliance Matters”).

C. Borrowers have requested that Agent and Lenders amend the Credit Agreement as set forth herein, and Agent and the Lenders are, subject to the terms hereof, willing to amend the Credit Agreement.

NOW, THEREFORE, in consideration of the premises set forth herein and for other good and valuable consideration, the receipt and sufficiency of which hereby are acknowledged, each of the undersigned hereby agrees as follows:

1. Amendments to Credit Agreement.

2. Waiver. Effective as of the date hereof, upon satisfaction of the conditions set forth in Section 3 of this Agreement, the Agent and the Lenders waive the Noncompliance Matters to the extent such Noncompliance Matters constitute a Default or an Event of Default under the Credit Agreement or the other Loan Documents. Provided that each of the Borrowers complies with all of the requirements contained in this Amendment and the Loan Documents, the Agent and Lenders shall forbear from enforcing their respective remedies with respect to any Default or Event of Default deemed to have occurred as a result of the Noncompliance Matters. If at any time any of the Borrowers fails to comply with any of the requirements set forth herein or if any additional Default or Event of Default occurs under this Amendment, the Credit agreement or the other Loan Documents, Agent and Lenders may immediately commence, proceed or otherwise continue with any or all rights and remedies available under the Loan Documents, under applicable law or otherwise without demand or notice to any Borrower, but as among Agent and Lenders, subject to the provisions of the Credit Agreement with respect to exercising remedies. Lenders and Agent are entering into this Amendment as an accommodation to the Borrowers and the Borrowers remain bound to perform their respective obligations under the Loan Documents.

3. Conditions. The effectiveness of this Amendment is subject to the following conditions precedent:

4. Representations and Warranties.

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5. Miscellaneous.

Except as expressly set forth herein, nothing contained in this Amendment shall be deemed to be an amendment or modification of any provision of any Loan Documents or any right, power or remedy of Agent or Lenders, nor constitute a waiver of any provision of any Loan Document, or any other document, instrument and/or agreement executed or delivered in connection therewith or of any Default or Event of Default under any of the foregoing, in each case whether arising before or after the date hereof or as a result of performance thereunder. This Amendment shall not preclude the future exercise of any right, remedy, power or privilege available to the Agent or Lenders, whether under the Loan Documents, at law or otherwise.

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[Signature Page Follows]

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IN WITNESS WHEREOF, this Amendment has been duly executed by each of the undersigned as of the day and year first set forth above.

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