Sec Form 4 Filing - AAMOTH WILLIAM L @ STERIS CORP - 2013-01-25

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 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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1. Name and Address of Reporting Person AAMOTH WILLIAM L 2. Issuer Name and Ticker or Trading Symbol STERIS CORP [ STE] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) V P - Corporate Treasurer (Last) (First) (Middle) 5960 HEISLEY ROAD 3. Date of Earliest Transaction (MM/DD/YY) 01/25/2013 (Street) MENTOR, OH44060 4. If Amendment, Date Original Filed (MM/DD/YY) 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 Shares, No Par Value 01/25/2013 M 2,000 A $ 27.45 10,027 D Common Shares, No Par Value 01/25/2013 S( 1 ) 2,000 D $ 37.4678 ( 2 ) 8,027 D Common Shares, No Par Value 01/28/2013 M 4,525 A $ 27.68 12,552 D Common Shares, No Par Value 01/28/2013 S( 3 ) 4,525 D $ 37.68 8,027 ( 4 ) D Common Shares, No Par Value 500 I See Footnote Below. ( 5 ) Common Shares, No Par Value 635 I See Footnote Below. ( 6 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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 Employee Stock Option Exercise $ 27.45 01/25/2013 M 2,000 ( 7 ) 09/12/2016 Common Shares, No Par Value 2,000 $ 0 0 D Employee Stock Option Exercise $ 27.68 01/28/2013 M 4,525 ( 8 ) 07/27/2017 Common Shares, No Par Value 4,525 $ 0 0 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other AAMOTH WILLIAM L 5960 HEISLEY ROAD MENTOR, OH44060 V P - Corporate Treasurer Signatures /s/ Dennis P. Patton, Authorized Representative under Power of Attorney 01/29/2013 Signature of Reporting Person Date

Explanation of Responses:

( 1 )These open market sales of a total of 2,000 Common Shares is pursuant to a Rule 10b5-1 Stock Trading Plan entered into by the Reporting Person on August 3, 2012. ( 2 )This represents the average sales price of the shares sold. The actual 7 sales prices ranged from $37.45 per share to $37.50 per share. Issuer, upon request by the SEC staff, will provide full information regarding the number of shares sold at each of these 7 sales prices. ( 3 )These open market sales of a total of 4,525 Common Shares is pursuant to a Rule 10b5-1 Stock Trading Plan entered into by the Reporting Person on August 3, 2012. ( 4 )5,280 of these Common Shares are restricted. The restrictions on these Common Shares lapse as follows: 2,680 on May 20, 2014, 500 on May 31, 2013, 500 on June 2, 2014, 500 on June 1, 2015, 275 on May 30, 2013, 275 on May 30, 2014, 275 on June 1, 2015 and 275 on May 31, 2016. ( 5 )Represents an investment by Mr. Aamoth in his Vanguard William L. Aamoth - Rollover IRA Brokerage Account. ( 6 )Represents 647.944 units of the STERIS Corporation 401(k) Plan STERIS Stock Fund which equals 635 Common share equivalents as of January 28, 2013. ( 7 )These options became exercisable as follows: 500 on November 1, 2008, 500 on November 1, 2009, 500 on November 1, 2010 and 500 on November 1, 2011. ( 8 )These options became exercisable as follows: 1,131 on July 27, 2008, 1,131 on July 27, 2009, 1,131 on July 27, 2010 and 1,132 on July 27, 2011.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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