<PAGE>
Exhibit 2
AMENDMENT AGREEMENT
AMENDMENT AGREEMENT dated as of December 14, 2000 by and among Robert Bosch
GmbH, a limited liability company organized under the laws of Germany
("Parent"), Bosch Security Systems Corporation, a New York corporation (the
"Purchaser"), and Detection Systems, Inc., a New York corporation (the
"Company").
WHEREAS, Parent and the Company have entered into an Agreement and Plan of
Merger dated as of December 10, 2000, to which the Purchaser subsequently became
a party (the "Merger Agreement"); and
WHEREAS, the parties desire to amend the Merger Agreement in certain
respects;
NOW, THEREFORE, in consideration of the foregoing and the representations,
warranties, covenants and agreements set forth herein and in the Merger
Agreement, the parties hereto, intending to be legally bound hereby, agree as
follows:
1. Amendment of Section 3.4. Section 3.4 of the Merger Agreement is
hereby amended to delete the words "a majority" in the first and second
sentences and to insert in place of such words, in each of such sentences, the
phrase "two-thirds".
2. Amendment of Section 3.17. Section 3.17 of the Merger Agreement is
hereby amended to delete the words "a majority" and to insert in place of such
words the phrase "two-thirds".
3. Amendment of Annex A. Clause (i) of the second sentence of the
introductory paragraph of Annex A to the Merger Agreement is hereby amended to
delete the words "a majority" and to insert in place of such words the phrase
"two-thirds".
4. Other Provisions Unaffected. Except as set forth above, this
Amendment Agreement shall not constitute a modification or amendment of any
other provision of the Merger Agreement or any other agreements executed in
connection therewith.
<PAGE>
IN WITNESS WHEREOF, Parent, the Purchaser and the Company have caused this
Agreement to be signed by their respective officers thereunto duly authorized as
of the date first written above.
Robert Bosch GmbH
By: /s/ Martin Reuter
--------------------
Name: Martin Reuter
Title: Director
By: /s/ Dr. Heiko Carrie
---------------------
Name: Dr. Heiko Carrie
Title: Director
Detection Systems, Inc.
By: /s/ Karl H. Kostusiak
---------------------
Name: Karl H. Kostusiak
Title: Chairman and CEO
Bosch Security Systems Corporation
By: /s/ Luke Baer
---------------
Name: Luke Baer
Title: Vice President
2