In About Electronic Evidence, computers expert witness Ernesto F. Rojas of Forensic & Security Services Inc. writes:
Electronic Evidence, also known as Digital Evidence, is any information which has been stored or transmitted in digital form and may be used in a court of law. Current trends indicate that more than 95% of all information exists solely in electronic form and never gets printed. Electronic records may include corporate plans, design plans, intellectual property, medical records, financial records, photos, spending histories, browser histories, etc.
Most person to person communications are electronic in nature, leaving a digital fingerprint. These communications include e-mail, instant messaging, texting, cell phones, and even land-based VOIP telephones. Volatile information derived from these communications might include financial information and transactions, schedules, timelines, and even the location of a defendant at a specific time.
In recent years, civil litigation has begun to demand that attorneys work with electronically stored information (ESI). ESI is highly volatile, easy to change or destroy, and requires immediate attention for preservation. Collection of ESI requires professionally trained personnel. In Texas, collection of ESI requires licensure by the State of Texas’ Private Security Board.