Charlie Tan admitted to killing his father in an affidavit filed in federal court on Monday. The now-23-year-old man is serving a 20 year sentence in prison for federal weapons charges. Tan admitted he received a firearm with intent to commit an offense, gave a false statement during the purchase of a firearm, as well as aiding and abetting, and willfully causing a federal offense. The gun was used to kill Jim Tan at the family's home in Pittsford in February 2015. Tan's attorney, Joel Rudin, wants the judge to vacate Tan's 20-year sentence. According to court papers, Jim Tan was abusive leaving Charlie psychologically scarred. Tan's lawyers, James Nobles and Brian DeCarolis, did not provide reports about abuse during Charlie's gun charge sentencing.