AFTER Danny G. Hopkins's Cadillac CTS rear-ended Lindsay Kyle's Dodge Neon at a traffic light in Rochester a year ago, witnesses said Mr. Hopkins had been zooming down the road, and crash investigators who examined the condition and location of the wreckage estimated that Mr. Hopkins was traveling 65 to 70 miles an hour at the point of impact.
But in a trial that ended on Oct. 7, a witness emerged with more to say: that four seconds before the crash, it had been traveling 106 m.p.h.
The witness in the case was an event data recorder, an automotive equivalent of the black boxes used to reconstruct plane crashes. A jury convicted Mr. Hopkins of second-degree manslaughter, a crime whose elements include recklessness and which carries a penalty of up to 15 years in jail.
"Clearly the black box technology played a large part in the jury's finding of guilty," said Richard C. Roxin, the assistant...