Longtime Pennsylvania Sen. Arlen Specter was confirmed dead by his son Sunday, according to The Associated Press. The 82-year-old legislator succumbed to non-Hodgkin’s lymphoma at his Philadelphia home. Specter first made his mark on Washington as an assistant counsel for the Warren Commission, investigating the assassination of President John F. Kennedy. He served two terms as Philadelphia district attorney, but lost a bid to become mayor of the city in 1967. He ran for a Senate seat in 1980 and took office the next year. He would serve for three decades. He briefly considered a presidential run in 1995, but dropped out after a few months.