X0306 4 2017-03-02 0 0001375557 Guidance Software, Inc. GUID 0001640807 Dennis Patrick 1055 COLORADO BLVD. PASADENA CA 91106 1 1 0 0 CEO and President Common Stock 2017-03-02 4 S 0 14948 6.76 D 849223 D Represents a sale, pursuant to a Section 10b5-1 Plan, to cover tax withholding obligations upon vesting of certain restricted shares of common stock that were granted under the Company's 2004 Second Amended and Restated Equity Incentive Plan, which grant was exempt from Section 16b. /s/ Patrick Dennis 2017-03-03