David Zimmerman, chief executive of Clearwater, Fla.-based data recovery firm LC Technology International, said investigators have a strong chance of accessing the data from any water-submerged digital devices even if they've been in there for more than a week.
"The only real way to destroy this stuff is hit it with a hammer," Zimmerman said. "Once you break that chip or disk, there's no way to reassemble it. Brute physical damage is the only surefire way to damage it."
Recovering data from a wet drive involves first drying it, sometimes by submerging it in different types of cleaning alcohols. Cleaning can be extra cumbersome in the case of saltwater immersion, which could lead to more corrosion on and around the hard drive that needs cleaning.
Next, investigators would determine if the device itself still works. The parts attached to a hard drive might get damaged by water, which is why a smartphone sunk in a toilet might never turn on again. But the hard drive or memory -- even if not inside an airtight, sealed compartment -- should remain intact. Fortunately, the connecting parts are replaceable.
Zimmerman's firm uses a 3-D printer to build custom sockets and connectors that can copy data off drives and make the information searchable on computers. He said he's trained FBI, military and other authorities on how to use similar processes.
"You could theoretically dry it off and put new parts on it, and it should work the way it did before it got tossed into the water," Zimmerman said. "The electronics on the outside are theoretically interchangeable."
The same goes with trying to use fire to melt a drive or blow it up. He's seen drives come out of house fires with data unscathed. The best option is to be paranoid and "beat it to a pulp," he said.
Essentially, the type and extent of damage inflicted can vary the chances of recovery from zero to "highly likely," said Heather Skinner, a spokeswoman for hard drive maker Western Digital.
On Dec. 2, married couple Syed Rizwan Farook and Tashfeen Malik opened fire on a holiday party at the Inland Regional Center in San Bernardino, killing 14 and injuring several more. They were killed hours later in a police shootout.
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