X0306 4 2017-05-24 0 0001375557 Guidance Software, Inc. GUID 0001383330 McCreight Shawn 3060 SAN PASQUAL ST. PASADENA CA 91106 0 0 1 0 0001383316 McCreight Jennifer 3060 SAN PASQUAL ST. PASADENA CA 91106 0 0 1 0 Common Stock 2017-05-24 4 S 0 25000 6.40 D 5103288 I Trustee and trust beneficiary The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $6.35 to $6.50, inclusive. The reporting person undertakes to provide to Guidance Software Inc., any security holder of Guidance Software Inc., or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (1) to this Form 4. /s/Michael Aspell, Attorney in Fact 2017-05-25 /s/Alfredo Gomez, Attorney in Fact 2017-05-25