Exhibit 99.1

Guidance Software Reports Q4 2011 Financial Results

PASADENA, Calif. – February 7, 2012 –

Guidance Software, Inc. (NASDAQ: GUID) today reported financial results for the fourth quarter and year ended December 31, 2011, setting new highs for revenue and earnings per share.

Fourth quarter 2011 financial highlights, calculated in accordance with GAAP, include:

On a non-GAAP basis, which excludes share-based compensation and amortization of intangibles, the company reported pre-tax net income of $3.9 million, or $0.16 per share, in the fourth quarter of 2011, compared to non-GAAP pre-tax net income of $1.2 million, or $0.05 per share, in the fourth quarter of 2010.

Guidance Software President and Chief Executive Officer Victor Limongelli said, “The fourth quarter marked an outstanding finish to 2011, with both revenue and net income reaching all-time highs. Propelling these results is the increasing penetration of our EnCase^® Enterprise platform. Marking a continuation of the positive momentum we experienced throughout the year, we added an impressive number of new EnCase Enterprise customers: 98 new customers during the fourth quarter and 285 for the full year. With each new EnCase Enterprise customer, we recognize the opportunity to highlight additional products built on top of our platform, including EnCase eDiscovery and EnCase Cybersecurity, as well as our training and professional services offerings. Importantly, the accelerating adoption of our suite of products provides us significant margin expansion in our operating model, as evidenced by our ability to deliver our best-ever fourth quarter non-GAAP operating margin of 13%.”

Mr. Limongelli continued, “Looking ahead, we are very optimistic about our prospects in 2012. Today we announced our entry into a definitive agreement to acquire CaseCentral, Inc., a privately held e-discovery leader for Cloud-based review and production software for corporations and law firms. Upon closing, this acquisition will extend Guidance Software’s market leadership by delivering a complete and integrated platform for the e-discovery needs of corporate and government customers. We continue to forecast strong top and bottom line growth and expect to further extend our market leadership in 2012 with the release of EnCase Enterprise Version 7 early in the year. We look forward to continuing to deploy the EnCase family of products designed to address the challenges created by the unstructured, unmanaged digital data that prevail throughout today’s business corporations and government agencies.”

Fourth Quarter 2011 Highlights and Recent Noteworthy Events

2012 Financial Outlook:

The company is initiating its guidance for the year ended December 31, 2012, as follows, and assumes that the acquisition of CaseCentral will occur in the second half of Q1 2012:

Conference Call Information:

The company will host a conference call today at 2:00 p.m. Pacific time, 5:00 p.m. Eastern time to discuss its quarterly results. Participants should call (877) 303-9850 (North America) or (408) 427-3732 (International) and should dial in at least 5 minutes prior to the conference call.

A webcast and replay of the call may also be found on the Internet through Guidance Software's Investor Relations website at http://investors.guidancesoftware.com/events.cfm. Registered users may access this content over the Internet, and there is no cost to register. If you have not already registered, please do so at least 15 minutes prior to the start of the conference call.

An audio-only replay of the call will be available by calling (404) 537-3406, passcode 41017140, available from 5:00 p.m. Pacific time, 8:00 p.m. Eastern time, February 7, 2012, through 9:00 p.m. Pacific time, midnight Eastern time, February 14, 2012.

About Guidance Software, Inc.

Guidance Software is recognized worldwide as the industry leader in digital investigative solutions. Its EnCase platform, with more than 40,000 licenses distributed worldwide, provides the foundation for government, corporate and law enforcement organizations to conduct thorough, network-enabled, and court-validated computer investigations of any kind, such as responding to e-discovery requests, conducting internal investigations, responding to regulatory inquiries or performing data and compliance auditing—all while maintaining the integrity of the data. The EnCase Enterprise platform is used by numerous Federal Civilian and Defense agencies, more than 60 of the Fortune 100, and thousands attend Guidance Software's renowned training programs annually. For more information about Guidance Software, visit www.guidancesoftware.com.

EnCase^®, EnScript^®, FastBloc^®, EnCE^®, Guidance Software™ and Tableau™ are registered trademarks or trademarks owned by Guidance Software in the United States and other jurisdictions and may not be used without prior written permission. All other trademarks and copyrights referenced in this press release are the property of their respective owners.

Forward Looking Statements:

This news release contains forward-looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Investors are cautioned that forward-looking statements in this release involve risks and uncertainties that could cause actual results to differ materially from current expectations. There can be no assurance that demand for the Guidance Software's products will continue at current or greater levels, or that the Company will continue to grow revenues, or be profitable. There can be no assurances that strategic acquisitions of the Company, including the proposed acquisition of CaseCentral, will be completed when expected, or at all, or will ultimately be successful for the Company. There are also risks that the Guidance Software's pursuit of providing network security and eDiscovery technology, including Cloud-based review and production software, might not be successful, or that if successful, it will not materially enhance the Guidance Software's financial performance; that the Company could fail to retain key employees; that changes in customer requirements and other general economic and political uncertainties could impact the Guidance Software's relationship with its customers; and that delays in product development, competitive pressures or technical difficulties could impact timely delivery of next-generation products; and other risks and uncertainties that are described from time to time in Guidance Software's periodic reports and registration statements filed with the Securities and Exchange Commission. The Company specifically disclaims any responsibility for updating these forward-looking statements.

GUID-F

Guidance Software, Inc.

Unaudited Condensed Consolidated Statements of Operations

(in thousands, except per share amounts)

Guidance Software, Inc.

Calculation of Pre-Tax Non-GAAP Income

(unaudited)

(in thousands, except per share amounts)

Notes to Unaudited Condensed Consolidated Statements of Operations:

This press release and its attachments include the non-GAAP financial measures of income (loss) before income taxes excluding share-based compensation expense, acquisition-related expense, amortization of intangibles and certain state sales tax charges and non-GAAP income (loss) before income taxes per share excluding share-based compensation expense, acquisition-related expense, amortization of intangibles andcertain state sales tax charges, which are reconciled to net income (loss) and net income (loss) per share, respectively, which we believe are the most comparable GAAP measures. We use these non-GAAP financial measures for internal managerial purposes, when publicly providing our business outlook, and to facilitate period-to-period comparisons. We describe limitations specific to each non-GAAP financial measure below.

Management generally compensates for limitations in the use of non-GAAP financial measures by relying on comparable GAAP financial measures and providing investors with a reconciliation of the non-GAAP financial measures only in addition to and in conjunction with results presented in accordance with GAAP. We believe that these non-GAAP financial measures reflect an additional way of viewing aspects of our operations that, when viewed with our GAAP results, provide a more complete understanding of factors and trends affecting our business. These non-GAAP measures should be considered as a supplement to, and not as a substitute for, or superior to, net income (loss) and net income(loss) per share calculated in accordance with GAAP.

Non-GAAP income (loss) is defined as follows: GAAP net income (loss) before income taxes excluding share-based compensation expense, acquisition-related expense, amortization of intangiblesand certain state sales tax charges. Share-based compensation expense is recorded in accordance with the FASB Accounting Standards Codification (ASC 718) Compensation – Stock Compensation Topic (formerly Statement of Financial Accounting Standard No. 123R, “Share-Based Payment”) for equity awards to employees and directors. Management and the Board of Directors believe it is useful to review the supplemental non-GAAP financial measures, which excludes income taxes and expenses related to share-based compensation, acquisition-related expense, amortization of intangibles and certain state sales tax charges in evaluating the Company, its management team and business unit performance during a particular time period. Share-based compensation expense, acquisition-related expense, amortization of intangibles,certain state sales tax charges and income taxes are not the responsibility of operating managers and generally cannot be changed or influenced by management.

Additionally, we believe it is useful in measuring the Company’s performance to exclude expenses related to income taxes, share-based compensation expense, acquisition-related expense, amortization of intangiblesand certain state sales tax charges because it facilitates comparability with prior period information.

Accordingly, management and the Board of Directors do not consider these excluded costs for purposes of evaluating the performance of the business, and they exclude such costs when evaluating the performance of the Company, its business units and its management teams and when making decisions to allocate resources among the Company's business units.

Guidance Software, Inc.

Unaudited Condensed Consolidated Balance Sheets

(in thousands)

Guidance Software, Inc.

Unaudited Cash Flow Summary

(in thousands)