Car's 'black box' and what it tells
...For prosecutors, the machines have opened a new line of attack, enabling them to cite the black box as an impartial witness.
In 2005, a Florida court upheld the conviction of a man who crashed his Pontiac Grand Am into a car holding two teenagers, killing both. The EDR showed he was driving 103 m.p.h. just before the crash.
The defense argued that the data did not match other physical evidence in the case.
"They're right most of the time, almost all the time," said Jeffrey Wigington, a lawyer in Texas. "But I think people in law enforcement agencies view them as 100 percent accurate, and they're just not that precise."
The machines have "some real quirks," said Wigington, whose cases involve alleged car defects that result in death or catastrophic injury. In some Fords, he said, if the ignition is switched on after a crash, the EDR memory may be overwritten.