A method for preserving digital evidence of a computer misconduct, the method including the steps of: prior to the misconduct, installing an expansion card capable of retrieving and storing a memory image and register information from a digital electrical computer in which the expansion card is installed; connecting a switch to regulate the expansion card from a location other than the computer; at the time of the misconduct, using the switch to trigger the retrieving and storing of the memory image and the register information into the expansion card; and subsequent to the misconduct, extracting the expansion card to preserve digital evidence of the computer misconduct. This method can be carried out further by subjecting the memory image and register information from the expansion card with another computer to forensic analysis.