PITTSBURGH — A man serving a life term in the shooting death of a fellow hunter more than a dozen years ago is asking a federal judge to overturn his conviction on the grounds that his attorneys should have challenged deer DNA used to link him to the death.

Lawrence Cseripko, 65, of North Union Township was convicted in 2005 of killing Paul Joseph Horvat Jr., whose body was found in December 1997. Authorities used new technology in 2004 to match deer DNA obtained from the crime scene with venison taken from Cseripko’s freezer.

In an appeal filed on his own behalf, Cseripko calls that “junk science” and says it has never been validated. He says other hunters had motive and opportunity, and the gun was never found.