PASADENA, Calif.--(BUSINESS WIRE)--Guidance Software, Inc. (NASDAQ: GUID) today reported financial results for the first quarter ended March 31, 2015. First quarter 2015 financial highlights, calculated in accordance with generally accepted accounting principles (GAAP), include: Revenue of $25.0 million, compared to $25.4 million in the first quarter of 2014 Product revenue of $7.1 million, up from $6.9 million in the first quarter of 2014 Services and maintenance revenue of $16.4 million, up f