X0306 4 2016-09-09 1 0000005768 AMERICAN SCIENCE & ENGINEERING, INC. ASEI 0001237004 HELMER HAMILTON W C/O AMERICAN SCIENCE AND ENGINEERING, INC., 829 MIDDLESEX TURNPIKE BILLERICA MA 01821 1 0 0 0 Common Stock 2016-09-09 4 D 0 21046 37.00 D 0 D Stock Option 63.71 2016-09-09 4 D 0 7000 D 2008-09-13 2017-09-13 Common Stock 7000 0 D Stock Option 67.98 2016-09-09 4 D 0 7000 D 2009-09-11 2018-09-11 Common Stock 7000 0 D Stock Option 62.50 2016-09-09 4 D 0 7000 D 2010-09-10 2019-09-10 Common Stock 7000 0 D Stock Option 74.79 2016-09-09 4 D 0 7000 D 2011-09-08 2020-09-08 Common Stock 7000 0 D On September 9, 2016, pursuant to the Agreement and Plan of Merger among the issuer, OSI Systems, Inc. ("Buyer") and Apple Merger Sub, Inc., a wholly owned subsidiary of Buyer ("Merger Sub"), dated June 20, 2016 (the "Merger Agreement"), Merger Sub merged with and into the issuer (the "Merger"), with the issuer surviving the Merger as a wholly owned subsidiary of Buyer. Pursuant to the Merger Agreement, at the effective time of the Merger, the shares automatically converted into the right to receive $37.00 per share in cash. This option was cancelled for no consideration pursuant to the terms of the Merger Agreement. /s/ Michael J. Muscatello, as attorney-in-fact for Hamilton W. Helmer 2016-09-12