X0303 4 2010-02-26 0 0001375557 Guidance Software, Inc. GUID 0001197590 VAN SCHOONENBERG ROBERT G C/O GUIDANCE SOFTWARE, INC. 215 NORTH MARENGO AVE. SUITE 250 PASADENA CA 91101 1 0 0 0 Common Stock 26250 D Common Stock 2010-02-26 4 A 0 2000 5.15 A 13000 I See footnote On February 26, 2010, Robert G. van Schoonenberg made an open market purchase of 2,000 shares of the Common Stock of Issuer in the name of the Robert van Schoonenberg Trust, dtd March 11, 1998. /s/ Robert van Schoonenberg 2010-02-26