Former US senator Arlen Specter, a moderate Republican who became a Democrat at the end of his career, has died.
Specter died of complications from non-Hodgkins Lymphoma - a form of immune-system cancer - at home in Philadelphia, his family told US media on Sunday.
Specter, who was in the Senate between 1981 and 2010, was respected for his command of constitutional law and for his staunch stance as a political centrist.
In 2009 Specter defected from the Republican party, but the following year he lost the Democratic party primary, ending his Senate career.
Specter played a key role in several Supreme Court nominations, most notably during the nomination hearings of Clarence Thomas in 1991.
The one-time Philadelphia prosecutor first gained prominence in the 1960s as an assistant counsel on the Warren Commission, which investigated the assassination of John F Kennedy.