John Constantino, 64, from New Jersey, had burns so severe that authorities needed to use DNA and dental records to identify him

The man who set himself on fire on the National Mall and later died was identified Monday, though police have no more information on his possible reasons.

John Constantino, 64, of Mount Laurel, New Jersey, had burns so severe that authorities needed to use DNA and dental records to identify him. District of Columbia police spokesman Paul Metcalf in an emailed statement confirmed his identity.

Constantino poured the contents of a red canister of gasoline on himself in the center portion of the mall Friday afternoon. He then set himself ablaze, with passing joggers taking off their shirts to help put out the flames. Police had said he was conscious and breathing at the scene.

But he died Friday night at a Washington hospital where he had been airlifted.

Police are investigating the man's possible motives. Lt Pamela Smith of the US park police said she was not aware that he had carried any signs with him or had articulated a cause.

One witness, Katy Scheflen, said she did not hear the man say anything intelligible before he set himself on fire. But she said she did notice that another man with a tripod was standing nearby and had disappeared by the time the police had arrived. It was not immediately clear whether a recording exists.

"He appeared to be waiting for something to happen. After it happened, he was gone," Scheflen, a Justice Department lawyer, said of the man with the tripod.

"I can't say what the connection was between them or whether there was a connection," she added.

The fire occurred in a city with jangled nerves following a Sept. 16 mass shooting at the Washington Navy Yard that left 13 dead, including the gunman, and a high-speed car chase outside the US Capitol on Thursday. The chase ended with a woman being shot dead by police with a young child in the car.