Data Recovered From DVD Leads To Conviction, 24-Year Sentence

Lucas123 writes "The Santa Cruz, Calif. DA's office had been counting on a DVD with the recorded testimony of a victim in case against a serial rapist, but when they popped the video into the player, nothing came up — the disc was blank. To make matters worse, the cop who performed the original interview with the victim told the DA she never said she was 'forced,' so the judge wasn't going to allow the witness to testify in a case where her original statement to police was in conflict with her current testimony. After two local data recovery firms said there was no way to restore the data, a third was able to recover the police interview from two years earlier, which led the defendant to plead guilty earlier this month. Close call."

Comments

Only Meta-Data was damaged

[imaginaryelf]

"Our analysis showed there to be damage to the lead-in section of the data," Keith Gnagey, vice president of professional services for i365, said in an e-mail statement about the recovery effort. That meant any attempt "with normal playing software would not be able to get past the beginning of the data."

That's like the directory tree being messed up but the data being intact.

I can't believe the other "two local data recovery firms" got stumped by this simple problem.

Re:Only Meta-Data was damaged

[Compholio]

Almost sounds like a DVD that wasn't finalized in a direct-to-dvd camcorder.

I don't know about that, but I've run into this problem when there's dust on the disk when it's recorded. The laser etches the dust rather than the media, resulting in a disk that's got a small blank section.

Re:Only Meta-Data was damaged

[Belial6]

When my father owned a computer shop, he would regularly get people trying to sell him software that would let him do "data recovery". There was no way my father was qualified to do data recovery. He eventually focused only on printer repair because he found he wasn't really qualified to even do most PC work. That didn't stop the sales guys from trying to convince him that if he bought their software, he would do fine in the "data recovery" field.

So, it doesn't surprise me that two local data recovery firms got stumped. They probably ran the software they bought against the DVD and when nothing came up, they said it was unrecoverable.

Re:Only Meta-Data was damaged

[Hal_Porter]

Actually that makes me think of a hair brained scheme. The finger print is essentially a mask applied to the data. Your eyes can see it but the DVD drive error corrects it away because there are enough gaps in the mask where the original data 'shows through' for the error correction to correct away the errors.

Now it seems like if you could record raw data you could make a DVD with a pattern visible to the naked eye but invisible to the DVD reader. So rather than waiting ages and buying expensive media for things like Lightscribe or Labelflash you could burn both the data and the label at the same time and on any media. Unlike DiscT@2 which burned logos on the data side of the disk, the space can be used for both logo and data at the same time.

You could do it with arbitrary bitmaps too - take the bitmap and make holes in it through which enough data shows through to make the disk readable. The burning software could do this with a mask cunningly constructed to make enough holes even in a solid bitmap to make the disk readable. Hell you could let the user select the tradeoff between image quality and error margin.

There's a a downside of course, the more solid the image the more the error correction will be stressed even for a disc which can be read perfectly. It seems like a disc burned with this technology would be less resistant to scratches and fingerprints.

Re:eep

[lysergic.acid]

i was thinking in the same direction too. but when i read this part of the summary:

but when they popped the video into the player, nothing came up -- the disc was blank.

my immediate question was, "did they try a PAL player?"

what's interesting to me is that two "data recovery firms" told them that the data was unrecoverable, but Seagate Recovery Service was able to recover the data without a problem. that makes me wonder if the earlier data recovery firms even tried to diagnose the problem or if they even knew anything about digital media & data storage. perhaps they thought that just by buying some digital forensics or data recovery software that automatically qualifies them to run a data recovery service. though i'm guessing that's what most police departments do as well.

i guess that's the problem with buying off the shelf software to do your job rather than learning how things work for yourself.