FILE- In this Aug. 27, 2015 file photo, Suffolk County District Attorney Thomas J. Spota points to a photograph of the aftermath of a deadly automobile accident on New York’s Long Island, during a news conference in Happague, N.Y. In the prosecution of the man charged with the accident, the District Attorney’s Office is employing a forensic technique that estimates a person’s blood alcohol content at the time of an offense, based on its level at the time it was read. Some experts question the accuracy of the technique known as “retrograde extrapolation:” labeling it junk science. (AP Photo/Frank Eltman, File)