Exhibit 99.1

INVESTOR CONTACT	MEDIA CONTACT
Rasmus van der Colff	Alex Andrianopoulos
Guidance Software, Inc.	Guidance Software, Inc.
626-768-4607	626-229-9191
investorrelations@guidancesoftware.com	newsroom@guidancesoftware.com

Guidance Software Reports 2013 Third Quarter Financial Results

• Revenue of $28.3 million; Non-GAAP net loss of ($0.09) per share

• 51 new EnCase^® Enterprise platform customers

• Releases industry’s first proactive endpoint security analytics solution, EnCase^® Analytics

PASADENA, Calif. – November 5, 2013 – Guidance Software, Inc. (NASDAQ: GUID) today reported financial results for the third quarter ended September 30, 2013.

Third quarter 2013 financial highlights, calculated in accordance with generally accepted accounting principles (GAAP) include:

• Revenue of $28.3 million, compared to $36.1 million in the third quarter of 2012

• SaaS revenues of $2.7 million, compared to $2.6 million in the third quarter of 2012

• Product revenue of $9.7 million, compared to $17.4 million in the third quarter of 2012

• Services and maintenance revenue of $15.9 million, compared to $16.1 million in the third quarter of 2012

• Net loss of $5.0 million, or ($0.19) per share, compared to net income of $1.3 million, or $0.05 per share, in the third quarter of 2012

On a non-GAAP basis, which excludes share-based compensation and amortization of intangibles, the Company reported a pre-tax net loss of $2.3 million, or ($0.09) per share, in the third quarter of 2013, compared to non-GAAP pre-tax net income of $4.1 million, or $0.15 per diluted share, in the third quarter of 2012.

Guidance Software President and Chief Executive Officer Victor Limongelli said, “Our third quarter results met our expectations, as our business began to improve from the first half of the year. Product revenues for the third quarter increased 26% sequentially and we added 51 new EnCase^® Enterprise customers. Most importantly, during the third quarter we introduced our newest product, EnCase^® Analytics, the industry’s first proactive endpoint security analytics solution. The introduction of EnCase^® Analytics builds upon Guidance Software’s overall strategy of ‘EnCase^® Everywhere’ and is a testament to our Company’s ability to create innovative products that meet and exceed the needs of our customers.”

Third Quarter 2013 Highlights and Noteworthy Events

• In September, the Company announced that its newest product, EnCase^® Analytics, is now generally available to the market through Guidance Software as well as channel partners. EnCase^® Analytics exposes unknown and difficult-to-detect threats by applying “big data” analytical techniques to the reams of data generated by endpoint activity, producing a clear picture of organization-wide security risk through an interactive visual interface. For the first time, IT security teams can take a proactive approach to threat surveillance by collecting and analyzing activity across all endpoints—including servers—on their network to reveal both external and internal threats.

• In the third quarter of 2013, the Company added 51 new EnCase^® Enterprise customers. The Company also added 17 customers of EnCase^® eDiscovery or EnCase^® Cybersecurity, which are built on the EnCase^® Enterprise platform.

• The Company released the results of a survey conducted during the Guidance’s 13^th Annual Computer and Enterprise Investigations Conference (CEIC) held this past May. The respondents, which include more than 150 organizations, indicated shifting priorities in enterprise and government security teams with the “length of time to resolve attacks” coming in as the primary cybersecurity concern. EnCase^® Cybersecurity and EnCase^® Analytics help organizations reduce the gap between detecting an incident and mobilizing a rapid response.

• EnCase^® App Central downloads have exceeded 15,000 since the online store opened in spring 2013. EnCase^® App Central has become a trusted source for developers and investigation professionals to share and discover the latest apps that complement the Company’s EnCase^® solutions. In addition, Belkasoft^®, a developer of forensic analysis tools, published its entire Evidence Center product line on the EnCase^® App Central.

• The Company introduced the Tableau T3iu Forensic SATA Imaging Bay, which adds SATA imaging capacity to forensic workstations via USB 3.0 bandwidth and provides fast and efficient SATA hard-drive acquisitions.

2013 Financial Outlook:

The Company is maintaining its guidance for the year ending December 31, 2013:

• Revenue for 2013 is expected to be in the range of $112 million to $115 million.

• Non-GAAP pre-tax earnings for 2013 are expected to be in the range of a $0.50 per share loss to a $0.42 per share loss.

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 (855) 859-2056, passcode 70989535, available from 8:00 pm eastern time, November 5, 2013, through midnight eastern time, November 12, 2013.

About Guidance Software:

Guidance Software is recognized worldwide as the industry leader in digital investigative solutions. Its EnCase^® Enterprise platform is used by numerous government agencies, more than 65 percent of the Fortune 100, and more than 40 percent of the Fortune 500, to conduct digital investigations of servers, laptops, desktops and mobile devices. Built on the EnCase^® Enterprise platform are market-leading electronic discovery and cyber security solutions, EnCase^® eDiscovery, EnCase^® Cybersecurity, and EnCase^® Analytics. They empower organizations to respond to litigation discovery requests, perform sensitive data discovery for compliance purposes, conduct speedy and thorough security incident response, and reveal previously hidden advanced persistent threats or malicious insider activity. For more information about Guidance Software, visit www.encase.com.

EnCase^®, EnScript^®, FastBloc^®, EnCE^®, EnCEP^®, 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.

Notes to Unaudited Condensed Consolidated Statements of Operations:

Guidance Software reports its financial results in accordance with generally accepted accounting principles, or GAAP. To supplement this information, we present in this release total non-GAAP revenue, gross profit, operating expenses, operating income (loss) and net income (loss), as well as non-GAAP net income (loss) per share. Total non-GAAP revenue consists of GAAP revenue as reported and adds back the acquisition-related deferred revenue adjustment booked for GAAP purposes. Non-GAAP gross profit consists of GAAP gross profit as reported and adds back the acquisition-related deferred revenue adjustment and stock-based compensation expense booked for GAAP purposes. Non-GAAP operating income (loss) consists of GAAP operating income (loss) as reported and adds back the acquisition-related deferred revenue adjustment booked for GAAP purposes and excludes amortization of intangibles, acquisition-related expenses and share-based compensation expense. Non-GAAP net income (loss) consists of GAAP operating income (loss) as reported and adds back the acquisition-related deferred revenue adjustment booked for GAAP purposes and excludes amortization of intangibles, acquisition-related expenses and share-based compensation expense.

Non-GAAP net income (loss) also excludes the tax provision.

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.

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.

Acquisition-related Deferred Revenue. Acquisition-related deferred revenue adjustment reflects the fair value adjustment to deferred revenues acquired in business combinations. The fair value of deferred revenue represents an amount equivalent to the estimated cost plus an appropriate profit margin, to perform services related to the acquiree’s software and product support, which assumes a legal obligation to do so, based on the deferred revenue balances as of the acquisition date. Guidance Software adds back this deferred revenue for its non-GAAP financial measures because it believes the inclusion of this amount directly correlates to the underlying performance of Guidance Software operations and facilitates comparisons of pre-merger results of legacy Guidance Software and CaseCentral to that of the Company’s post-merger results.

Acquisition-related Expenses. Acquisition-related expenses are fees and expenses, including legal, investment banking and accounting fees and other integration-related expenses, incurred in connection with announced transactions. Guidance Software excludes acquisition-related expenses from non-GAAP operating income and non-GAAP net income because it believes (i) the amount of such expenses in any specific period may not directly correlate to the underlying performance of Guidance Software business operations and (ii) such expenses can vary significantly between periods.

Amortization of Intangibles. Amortization of intangibles is a non-cash expense arising from the acquisition of intangible assets in connection with acquisitions. Guidance Software excludes acquisition-related amortization expense from non-GAAP operating income and non-GAAP net income because it believes (i) the amount of such expenses in any specific period may not directly correlate to the underlying performance of Guidance Software business operations and (ii) such expenses can vary significantly between periods as a result of new acquisitions and full amortization of previously acquired intangible assets. Investors should note that the use of these intangible assets contributed to revenue in the periods presented and will contribute to future revenue generation and the related amortization expense will recur in future periods.

Stock-based Compensation Expense. Stock-based compensation expense is a non-cash expense arising from the grant of stock awards to employees. Guidance Software excludes stock-based compensation expense from non-GAAP operating income and non-GAAP net income because it believes (i) the amount of such expenses in any specific period may not directly correlate to the underlying performance of Guidance Software business operations and (ii) such expenses can vary significantly between periods as a result of the timing of grants of new stock-based awards, including grants in connection with acquisitions. Investors should note that stock-based compensation is a key incentive offered to employees whose efforts contributed to the operating results in the periods presented and are expected to contribute to operating results in future periods and such expense will recur in future periods.

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 are also risks that the Guidance Software’s pursuit of providing network security and eDiscovery technology 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.

Guidance Software, Inc.

Unaudited Condensed Consolidated Statements of Operations

(in thousands, except per share amounts)

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
	2013			2012			2013			2012
Revenues:
Product revenue	$	9,728		$	17,394		$	24,953		$	39,945
Subscription revenue		2,711			2,648			8,202			6,716
Services and maintenance revenue		15,875			16,099			49,409			46,567
Total revenues		28,314			36,141			82,564			93,228
Cost of revenues:
Cost of product revenue		2,164			2,208			5,665			5,795
Cost of subscription revenue		1,109			981			3,289			2,850
Cost of services and maintenance revenue		6,432			6,539			19,961			18,086
Total cost of revenues		9,705			9,728			28,915			26,731
Gross profit		18,609			26,413			53,649			66,497
Operating expenses:
Selling and marketing		10,494			11,790			30,359			30,341
Research and development		6,771			6,224			21,438			17,807
General and administrative		4,271			5,351			14,155			16,664
Depreciation and amortization		1,983			1,745			5,673			5,335
Total operating expenses		23,519			25,110			71,625			70,147
Operating income (loss)		(4,910	)		1,303			(17,976	)		(3,650	)
Interest income and other, net		9			(9	)		18			(10	)
Income (loss) before income taxes		(4,901	)		1,294			(17,958	)		(3,660	)
Income tax provision		67			22			183			231
Net income (loss)	$	(4,968	)	$	1,272		$	(18,141	)	$	(3,891	)
Net income (loss) per share—basic	$	(0.19	)	$	0.05		$	(0.71	)	$	(0.16	)
Net income (loss) per share—diluted	$	(0.19	)	$	0.05		$	(0.71	)	$	(0.16	)
Shares used in per share calculation—basic		25,914			24,988			25,713			24,450
Shares used in per share calculation—diluted		25,914			26,543			25,713			24,450
Supplemental Financial Data
Non-GAAP income (loss) before income taxes excluding acquisition-related deferred revenue adjustment, acquisition-related expense, share-based compensation and amortization of intangibles	$	(2,305	)	$	4,065		$	(10,152	)	$	6,047
Non-GAAP income (loss) per share before income taxes excluding acquisition-related deferred revenue adjustment, acquisition-related expense, share-based compensation and amortization of intangibles
Basic	$	(0.09	)	$	0.16		$	(0.39	)	$	0.25
Diluted	$	(0.09	)	$	0.15		$	(0.39	)	$	0.23

Guidance Software, Inc.

Calculation of Pre-Tax Non-GAAP Income

(unaudited)

(in thousands, except per share amounts)

	Three Months Ended September 30,					Nine Months Ended September 30,
	2013			2012		2013			2012
Calculation of pre-tax non-GAAP (loss) income:
GAAP net income (loss)	$	(4,968	)	$	1,272	$	(18,141	)	$	(3,891	)
Add:
Income tax provision		67			22		183			231
Acquisition-related expense		—			214		—			2,420
Acquisition-related deferred revenue adjustment		—			420		253			1,048
Amortization of intangibles		577			668		1,899			2,014
Share-based compensation expense (including related payroll taxes paid by the Company)		2,019			1,469		5,654			4,225
Non-GAAP income (loss) before income taxes excluding acquisition-related deferred revenue adjustment, acquisition-related expense, share-based compensation and amortization of intangibles	$	(2,305	)	$	4,065	$	(10,152	)	$	6,047
Non-GAAP income (loss) per share before income taxes excluding acquisition-related deferred revenue adjustment, acquisition-related expense, share-based compensation and amortization of intangibles
Basic	$	(0.09	)	$	0.16	$	(0.39	)	$	0.25
Diluted	$	(0.09	)	$	0.15	$	(0.39	)	$	0.23
Shares used in per share calculations:
Basic		25,914			24,988		25,713			24,450
Diluted		25,914			26,543		25,713			26,020
Detail of Share-based Compensation Expense:
Cost of product revenue	$	35		$	25	$	100		$	72
Cost of subscription revenue		51			38		141			108
Cost of service and maintenance revenue		368			256		1,039			735
Selling and marketing		539			408		1,518			1,217
Research and development		544			365		1,479			990
General and administrative		482			377		1,377			1,103
Total share-based compensation expense	$	2,019		$	1,469	$	5,654		$	4,225
Detail of Acquisition-related Expense:
General and administrative	$	—		$	214	$	—		$	2,420
Detail of Acquisition-related Deferred Revenue Adjustment:
Subscription revenue	$	—		$	318	$	193		$	803
Services and maintenance revenue		—			102		60			245
Total acquisition-related deferred revenue adjustment	$	—		$	420	$	253		$	1,048

Guidance Software, Inc

Reconciliation of GAAP to Non-GAAP Financial Measures

(Unaudited and in thousands, except per share amounts)

	Three Months Ended September 30,						Nine Months Ended September 30,
	2013			2012			2013			2012
Total revenues, as reported	$	28,314		$	36,141		$	82,564		$	93,228
Acquisition-related deferred revenue adjustment		—			420			253			1,048
Total non-GAAP revenues	$	28,314		$	36,561		$	82,817		$	94,276
Gross profit, as reported	$	18,609		$	26,413		$	53,649		$	66,497
Acquisition-related deferred revenue adjustment		—			420			253			1,048
Share-based compensation		454			319			1,280			915
Gross profit adjustment		454			739			1,533			1,963
Total non-GAAP gross profit	$	19,063		$	27,152		$	55,182		$	68,460
Total operating expenses, as reported	$	23,519		$	25,110		$	71,625		$	70,147
Amortization of intangibles		(577	)		(668	)		(1,899	)		(2,014	)
Acquisition-related expenses		—			(214	)		—			(2,420	)
Share-based compensation		(1,565	)		(1,150	)		(4,374	)		(3,310	)
Operating expense adjustment		(2,142	)		(2,032	)		(6,273	)		(7,744	)
Total non-GAAP operating expenses	$	21,377		$	23,078		$	65,352		$	62,403
Operating income, (loss) as reported	$	(4,910	)	$	1,303		$	(17,976	)	$	(3,650	)
Gross profit adjustment		454			739			1,533			1,963
Operating expense adjustment		2,142			2,032			6,273			7,744
Total non-GAAP operating income (loss)	$	(2,314	)	$	4,074		$	(10,170	)	$	6,057
Net income, (loss) as reported	$	(4,968	)	$	1,272		$	(18,141	)	$	(3,891	)
Gross profit adjustment		454			739			1,533			1,963
Operating expense adjustment		2,142			2,032			6,273			7,744
Income tax provision		67			22			183			231
Total non-GAAP net income (loss)	$	(2,305	)	$	4,065		$	(10,152	)	$	6,047
Net income (loss) per share-diluted, as reported	$	(0.19	)	$	0.05		$	(0.71	)	$	(0.16	)
Non-GAAP net income (loss) per share-diluted	$	(0.09	)	$	0.15		$	(0.39	)	$	0.23

Guidance Software, Inc.

Unaudited Condensed Consolidated Balance Sheets

(in thousands)

	September 30,			December 31,
	2013			2012
ASSETS
Current assets:
Cash and cash equivalents	$	16,803		$	32,606
Trade receivables, net		21,806			23,558
Inventory		1,800			2,008
Prepaid expenses and other current assets		5,579			3,753
Total current assets		45,988			61,925
Long-term assets:
Property and equipment, net		19,078			10,227
Intangible assets, net		10,512			12,411
Goodwill		14,632			14,632
Other assets		1,355			2,026
Total long-term assets		45,577			39,296
Total assets	$	91,565		$	101,221
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable	$	6,494		$	3,058
Accrued liabilities		10,853			12,929
Capital lease obligations		209			393
Deferred revenues		36,095			37,337
Total current liabilities		53,651			53,717
Long-term liabilities:
Rent incentives		6,283			730
Deferred revenues		4,367			6,115
Contingent earn-out		397			569
Deferred tax liabilities		958			889
Other long-term liabilities		81			181
Total long-term liabilities		12,086			8,484
Stockholders’ equity:
Common stock		25			25
Additional paid-in capital		100,147			93,037
Treasury stock		(10,805	)		(8,644	)
Accumulated deficit		(63,539	)		(45,398	)
Total stockholders’ equity		25,828			39,020
Total liabilities and stockholders’ equity	$	91,565		$	101,221

Guidance Software, Inc

Unaudited Cash Flow Summary

(in thousands)

	Nine Months Ended September 30,
	2013			2012
Operating Activities:
Net loss	$	(18,141	)	$	(3,891	)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Depreciation & amortization		5,673			5,335
Provision for doubtful accounts		350			100
Share-based compensation		5,654			4,225
Deferred taxes		69			96
Loss on disposal of assets		107			82
Changes in operating assets and liabilities:
Trade receivables		1,401			3,080
Inventory		208			(494	)
Prepaid expenses and other assets		217			(696	)
Accounts payable		2,680			170
Accrued liabilities		2,620			(1,255	)
Deferred revenues		(2,990	)		(2,109	)
Net cash (used in) provided by operating activities		(2,152	)		4,643
Investing Activities:
Purchase of property and equipment		(11,921	)		(2,485	)
Acquisition, net of cash acquired		—			(9,642	)
Net cash used in investing activities		(11,921	)		(12,127	)
Financing Activities:
Proceeds from the exercise of stock options		1,456			2,655
Common stock repurchased or withheld		(2,161	)		(1,294	)
Principal payments on capital lease and other obligations		(1,025	)		(937	)
Net cash (used in) provided by financing activities		(1,730	)		424
Net decrease in cash and cash equivalents		(15,803	)		(7,060	)
Cash and cash equivalents, beginning of period		32,606			37,048
Cash and cash equivalents, end of period	$	16,803		$	29,988