Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^*

OPEN TEXT CORP

2. Date of Event Requiring Statement (MM/DD/YYYY) 9/14/2017

3. Issuer Name and Ticker or Trading Symbol

Guidance Software, Inc. [GUID]

(Last) (First) (Middle)

275 FRANK TOMPA DRIVE

4. Relationship of Reporting Person(s) to Issuer (Check all applicable)

_____ Director ___ X ___ 10% Owner
_____ Officer (give title below) _____ Other (specify below)

(Street)

WATERLOO, A6 N2L 0A1

(City) (State) (Zip)

5. If Amendment, Date Original Filed (MM/DD/YYYY)

6. Individual or Joint/Group Filing (Check Applicable Line)

_ X _ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock, par value $0.001 per share	1000 ⁽¹⁾	I ⁽²⁾	Through a wholly owned subsidiary ⁽¹⁾ ⁽²⁾

*Table II - Derivative Securities Beneficially Owned ( e.g.* , puts, calls, warrants, options, convertible securities)**
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivate Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security		6. Nature of Indirect Beneficial Ownership (Instr. 5)

Explanation of Responses:
(1)	On September 14, 2017, Open Text Corporation ("Parent") and Galileo Acquisition Sub Inc. ("Purchaser") completed the transactions contemplated by the Agreement and Plan of Merger, dated as of July 25, 2017, by and among Guidance Software, Inc. ( "Issuer"), Parent and Purchaser (the "Merger Agreement"). Pursuant to the terms of the Merger Agreement, Purchaser merged with and into Issuer (the "Merger"), with the Issuer surviving the Merger as a wholly-owned subsidiary of Parent (the "Surviving Corporation") and Purchaser ceasing to exist following the Merger. At the effective time of the Merger, the outstanding shares of common stock of Purchaser were converted into and became shares of the Surviving Corporation.
(2)	Prior to the Merger, Purchaser was a wholly-owned subsidiary of Rocket Holdco, Inc., which was a wholly-owned subsidiary of Parent. Subsequent to the Merger, Issuer is a wholly-owned subsidiary of Rocket Holdco, Inc., which is a wholly-owned subsidiary of Parent.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
OPEN TEXT CORP 275 FRANK TOMPA DRIVE WATERLOO, A6 N2L 0A1		X

Signatures
/s/ Gordon Davies, EVP, Chief Legal Officer and Corporate Development		9/19/2017
^** Signature of Reporting Person		Date

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 5(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.