<PAGE>
June 15, 2000
Ultrak, Inc.
1301 Water's Ridge Drive
Lewisville, Texas 75240
Karl H. Kostusiak
Detection Systems, Inc.
130 Perinton Parkway
Fairport, New York 14450
Re: 2000 Annual Meeting of Shareholders of
--------------------------------------
Detection Systems, Inc. (the "Company")
---------------------------------------
Dear Mr. Kostusiak:
Reference is made to the letter dated May 12, 2000 (the "Notice"), from
Cede & Co. to the Company. Cede & Co., a holder of record of shares of the
Company's common stock, delivered the Notice on behalf of the undersigned, the
beneficial owner of such shares. In the Notice, Cede & Co., acting on behalf of
the undersigned, nominated George K. Broady, Malcolm J. Gudis, Ronald F.
Harnisch, Robert L. Frome and William D. Breedlove for election as directors of
the Company at the Company's 2000 annual meeting of shareholders.
Please be advised that two of the five nominees, Messrs. Broady and Gudis,
determined subsequent to the date of the Notice not to stand for election as
directors of the Company. Therefore, the Holder hereby withdraws the nominations
of Messrs. Broady and Gudis. This withdrawal does not affect the status of the
nominations of Messrs. Harnisch, Frome and Breedlove, which shall remain in
effect.
Very truly yours,
ULTRAK, INC.
By: /s/ Mark L. Weintrub
------------------------------
Name: Mark L. Weintrub
Title: Secretary
