By and large, when a computer file or document is erased, deleted, put in the Recycling Bin or Trashcan, all or part of it still remains on the computer's disk drive. Even when it has been overwritten, most of the time, there is something relevant to be found, given the sheer size (billions of sectors!) and complexity of operating systems such as Windows, Macintosh, and others.
Some of the things we have found include:
Accidentally or intentionally deleted emails.
Encrypted files with the key thrown away or lost.
Files that with falsified dates.
Files that a series of data recovery houses couldn't find.
Files unintentionally damaged or overwritten by other consultants or technicians.
Databases on computers that have been completely erased, reformatted and reinstalled.
Files that were embedded in programs designed by consultants who are long gone.
Evidence of sabotage even when advanced data destruction programs have been used.
Files from completely scrambled computers.
Files from badly damaged computers.
Files from a computer that had a sledgehammer taken to it by a jealous spouse.
Files from computers and devices buried in sand, burned in fires, submerged in water, inundated with extinguishers, mistaken for litter boxes by pets or drenched in lattes and martinis.
Files from computers subjected to the same treatment by humans.
Files from more than 15,000 disk drives and other digital media.