CENTRAL ISLIP, N.Y. — The way prosecutors see it, Oneil Sharpe Jr. was drunk when he raced down a Long Island highway at nearly 100 mph this summer and slammed into a car carrying a family home from a church gathering, causing a fiery wreck that killed a father and his two children.
CENTRAL ISLIP, N.Y. — The way prosecutors see it, Oneil Sharpe Jr. was drunk when he raced down a Long Island highway at nearly 100 mph this summer and slammed into a car carrying a family home from a church gathering, causing a fiery wreck that killed a father and his two children.
Sharpe’s blood-alcohol reading, taken about four hours later, was 0.06 percent — below the legal threshold of 0.08. But he was still charged with drunken driving and vehicular homicide because a forensic technique estimated that his blood-alcohol level at the time of the crash actually was 0.12.
That technique, known as “retrograde extrapolation,” has been used to win convictions nationwide for decades, but has increasingly come under scrutiny by drunken-driving experts as an unreliable measure of a person’s intoxication. Some defense attorneys have even labeled it junk science.
“Government lawyers and puppet scientists know retrograde extrapolation is hogwash and will say so when it benefits them, but mostly they pretend otherwise because it is useful in gaining convictions,” said D. Timothy Huey, a Columbus, Ohio, attorney specializing in drunken-driving cases.
“Retrograde extrapolation is about as scientifically reliable as astrology,” added Jonathan Manley, a former prosecutor who is representing Sharpe in the Long Island crash. “It relies on the assumption that a person’s blood-alcohol content peaked prior to the arrest without any basis to prove that.”
While there are no national statistics to document the use of retrograde extrapolation, prosecutors in many states, including New York, North Carolina, Michigan, Colorado and Illinois, have offered evidence of estimated intoxication levels at trial. But courts in some other states have severely restricted its use, requiring prosecutors to use only the blood-alcohol readings taken at the time of a person’s arrest.
“The general rule in virtually every state is that it is up to a jury to decide its relevance,” said attorney Patrick Barone, who has written a textbook titled “Defending Drinking Drivers” and teaches a class at Western Michigan University’s law school that includes a two-hour lecture on retrograde extrapolation.