Hard drives forensic examiners tackle may be as little as 20 gigabytes, or some newer drives are 250 gigabytes, even up to 750 gigabytes.
Computer forensic examiners, using special computer forensic software, first acquire an image of the target media, then do an analysis.
A lot of the evidence you seek will not be visible to the untrained eye. You won't find it in a Word document by using Windows Explorer, or by starting a program from a shortcut on the desktop.
About the team
Dave Pettinari:
Dave Pettinari, a retired 20-year veteran of the Pueblo County, Colo., Sheriff's Office, now owns a computer forensics, Internet investigations, and private investigations consulting business.

Pettinari formerly was a commander of a high-tech crimes unit at the Pueblo County (Colorado) Sheriff's Office, including participation in the Colorado Internet Crimes Against Children Task Force. He and fellow officers arrested 36 online predators who go after children in chat rooms and in instant messaging.

He has taught numerous national and state-level seminars on use of the Internet for Law Enforcement Intelligence, Investigations, identity theft, and computer crime. In all, he has published 100+ articles in national publications over the years, about one-fourth of them on computer crime and Internet crime topics. He taught around the country with a course of his own invention since 1995 on computer crime, Internet crime and identity theft investigation. He is a former instructor for Internet Crimes Inc., and for Paraben Corp. on forensically processing and finding information on cell phones and PDAs.

Today, in addition to operating his businesses, he teaches multiple courses at two universities and a college.

Pettinari holds a master's degree in journalism from Marquette University in Milwaukee where he was a J.L. O'Sullivan fellow. He also holds a bachelor's degree in political science from Regis College in Denver. He graduated from St. Mary's High School in Colorado Springs.

A certified peace officer, he attended the School of Police Staff and Command at Northwestern University in Chicago. He has been trained in computer forensics, attending 36+ computer crime and computer forensics schools, to include the Federal Law Enforcement Center's "Criminal Investigations in an Automated Environment" course, SEARCH computer crimes, SEARCH Investigation of Online Sexual Exploitation of Children, EnCase (basic, intermediate and advanced), and the National White Collar Crime Center's Basic Data Recovery and Analysis course, Advanced Data Recovery and Analysis course, Internet Trace Evidence Recovery and Analysis course, and numerous other schools. He holds the EnCE designation, meaning he is EnCase certified.

He is a former president of the Southeastern Colorado Law Enforcement Association, and of the Southern Colorado Press Club. He served as president of Police Futurists International in 1999-2000.

A major in the U.S. Air Force Reserve, he served in Operation Desert Storm (England, Turkey and Saudi Arabia), and in Operation Provide Comfort, the airdrop mission to the Kurdish people. He served as a reserve member of the Air Force Office of Special Investigation, specializing in computer crimes investigation and anti-hacking. He was assigned to Travis AFB, CA, but served also at Peterson AFB in Colorado Springs. Pettinari is a graduate of Squadron Officers School and Air Command and Staff College.

In his military life, he was activated for a month to examine 500 gigabytes of information coming out of the Guantanamo, Cuba espionage investigation.

He retired from the Air Force Reserve in May 2005 after 21 years service.

                          Curriculum Vitae                     LINKEDin profile