Specter, who announced in late August that he was battling cancer, died at his home in Philadelphia from complications of non-Hodgkin lymphoma, said his son Shanin. Over the years, Arlen Specter had fought two previous bouts with Hodgkin lymphoma, overcome a brain tumor and survived cardiac arrest following bypass surgery.

Specter rose to prominence in the 1960s as an aggressive Philadelphia prosecutor and as an assistant counsel to the Warren Commission, developing the single-bullet theory that posited just one bullet struck both President Kennedy and Texas Gov. John Connally — an assumption critical to the argument that presidential assassin Lee Harvey Oswald acted alone.