An FBI affidavit says the soldier who was shot by police in Front Royal over the weekend was dressed up like "The Joker." The affidavit says Army Spc. Christopher Lanum idolized the Batman villain.

Lanum was accused of stabbing a fellow soldier at Fort Eustis. The attacked soldier says Lanum was wearing a Halloween costume of the Joker when he and his girlfriend, Patsy Montowski, attacked him with a stun gun.

The victim says, when he tried to run away, Lanum cut his throat twice with a knife.

Police say Lanum then drove 200 miles to Skyline Drive. Park rangers chased Lanum inside the Shenandoah National Park.

Police shot Lanum when they say he pointed a loaded shotgun at them.

Investigators say later they found a letter in Lanum's car, written from the couple to both of their families saying good-bye.

Lanum served 18 months in Iraq.