Investigators hit jackpot by recovering Tsarnaev's laptop, Rockville expert says

Some computer experts are saying the recovery of Dzhokhar Tsarnaev's laptop computer may be the greatest piece of evidence investigators will get their hands on in this case.

ABC7 talked with an expert in digital forensics who says even if Tsarnaev comes clean, the computer will still know more than he could ever remember.

When investigators recovered Tsarnaev's laptop, digital forensics expert Jared Stern of Rockville knew it was a major score for the feds.

"It would not be too dramatic to call it a touchdown, a jackpot," Stern says. "It's very possible the computer holds key information that he won't even remember."

Computers save everything - even if you tried to delete or encrypt the data.

Stern draws an example of a hard drive - the small bottom portion represents the files you actually can see on your computer.

What's supremely important is the vast area called unallocated space.

That space can potentially store every email, webchat, photo, document, and a record of every website you've ever visited, even if you just looked at a website, even if you tried to cover your tracks.

"Even the people who are most careful, there is still more there than they think," Stern says. "And in this case I have a feeling there's going to be a lot."

Stern also shows how investigators can create a digital time-line of computer activity.

This is crucial data that Stern believes could easily lead to more arrests and strengthen the case against those already under arrest. The FBI now essentially has a digital record of everyone Tsarnaev communicated with for as long as he had that computer.

"From the radicalization point to the operational inception to its execution - anyone that contributed in any way may as well call the FBI now," Stern says. "Because they're on their way."

His computer would be even more valuable to investigators if Tsarnaev had it for awhile. Investigators could digitally dig back farther in time. They'll do the same thing with his cell phone.

Stern says it will likely take a few weeks to do a full, thorough sweep of the drive and that's when we may learn more about if anyone else was involved in the bombing.