Sandy Hook Elementary School shooter Adam Lanza may have tried to sabotage his own computer before going on a murderous rampage that claimed the lives of 20 children, but experienced investigators said today that law enforcement forensic experts could still recover critical evidence from the damaged drives.
Connecticut State Police Lt. Paul Vance revealed Monday that a computer crimes unit was working in conjunction with a forensics laboratory to "dissect" any evidence relevant to the case, but he declined to comment further on what type of evidence was involved and in what condition it was in. Later that day, law enforcement officials told ABC News that police recovered a badly damaged computer from Lanza's home that appeared to have been attacked by a hammer or screwdriver.
Sources said if they can still read the computer's hard drive, they hope to find critical clues that may help explain Lanza's motives in the killing.
Former FBI forensic experts told ABC News that in cases similar to this one, damage to the computer does not necessarily mean the computer files cannot be accessed.
"If he took a hammer to the outside, smashed the screen, dented the box, it's more than likely the hard drive is still intact," said Al Johnson, a retired FBI special agent who now works privately examining digital evidence and computer data. "And even if the hard drive itself is damaged, there are still steps that can be taken to recover everything."
Brett Harrison, a former FBI computer forensics expert who now works with a D.C. consulting firm, said that authorities have a great deal of technology at their disposal to retrieve that data. How much is recovered, he said, will depend entirely on how much damage was done to the well-insulated "platters" -- discs lodged deep inside the machine -- where Lanza's every digital footstep was recorded.
It is likely, he said, that Lanza's computer has been moved to a "clean room" where, if the discs are intact, they could be removed and then carefully re-inserted in a fresh hard drive. If the calibrations are done correctly, investigators would still be able to unlock the clues on the discs.
If the discs aren't in perfect condition, Harrison said, "There is equipment they can use to read the data off a record even if a portion of it is damaged."
Johnson said it is tedious work done in a clean environment because the tolerances of the discs is so precise – even a particle of dust could destroy crucial evidence.
"We're talking about a tolerance of less than a human hair," said Johnson, who now does computer forensics for a South Carolina-based investigative firm.
Police have not said exactly what they expect to find on the computer's hard drive, but the former FBI experts said typically there could be record of visits to violent web sites, or to online stores that sell ammunition, or to email that might reveal if Lanza shared any hints of his plans with others.
"I'm not big on speculation," Harrison said, "but you're talking about potentially finding all the normal things that people do with their computer – Facebook pages, internet activity, email, you name it."
For now, the FBI is keeping mum on what kind of computer forensic help it could be offering in the case.