SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the

Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) April 13, 2016

Guidance Software, Inc.

(Exact name of registrant as specified in its charter)

Delaware

(State or other jurisdiction of incorporation)

Registrant’s telephone number, including area code 626-229-9191

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

o                                    Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o                                    Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o                                    Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o                                    Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 2.02 Results of Operations and Financial Condition.

On April 13, 2016, Guidance Software, Inc. issued a press release announcing its preliminary results for the three-month period ended March 31, 2016. A copy of the press release is furnished as a part of this current report on Form 8-K as Exhibit 99.1 and is incorporated herein in its entirety by reference.

Exhibit 99.1 is being furnished pursuant to Item 2.02 and shall not be deemed “filed” for any purpose, including for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section. The information in this Current Report on Form 8-K shall not be deemed incorporated by reference into any filing under the Securities Act of 1933, as amended (the “Securities Act”), or the Exchange Act regardless of any general incorporation language in such filing.

Item 7.01 Regulation FD Disclosure.

As discussed in Item 2.02 above, we issued a press release regarding our first quarter 2016 preliminary results.

The information being furnished pursuant to Item 7.01 shall not be deemed “filed” for any purpose, including for the purposes of Section 18 of the Exchange Act, or otherwise subject to the liabilities of that section. The information in this Current Report on Form 8-K shall not be deemed incorporated by reference into any filing under the Securities Act or the Exchange Act regardless of any general incorporation language in such filing.

Item 9.01 Financial Statements, Pro Forma Financial Information and Exhibits.

(d) Exhibit

99.1                                                                                             Press Release, dated April 13, 2016, issued by Guidance Software, Inc.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.