A judge has declared a mistrial in the case of a Southwick man charged with being drunk when he was involved in a car crash that killed another driver. The Hampden Superior Court judge declared a mistrial Monday in the case of Daniel Leary, 37, after the jury learned the defendant had been charged with drug possession. The judge had previously ruled that the drug charge could not be introduced at trial. Prosecutors told The Republican that they plan to retry Leary. He is charged with motor vehicle homicide while under the influence of alcohol in the March 2011 crash that killed David Laduzenski, 29, in West Springfield.