A third teenager was charged with murder in the death of a homeless man who was severely beaten with a baseball bat and shot with a paintball gun.

William Ammons, 18, was charged Tuesday in the killing of 45-year-old Norris Gaynor, one of at least three homeless men allegedly attacked early Thursday by the teenage trio. He was scheduled to make an initial court appearance Wednesday.

Ammons, 18-year-old Brian Hooks and 17-year-old Thomas Daugherty all face murder and assault charges in the attacks, one of which was recorded by a security surveillance camera and broadcast on television around the world. The video played a key role in identifying the perpetrators.

Ammons had initially been accused only of assaulting another homeless man. He was released from jail on $5,000 bail on the assault charge but was arrested again a few hours later on the murder charge.

Police said Ammons admitted he shot Gaynor with a paintball gun and that his black 1997 Chevrolet was used by assailants in at least two of the attacks.

"I can't imagine what would go through somebody's mind or what they were thinking to commit a heinous crime such as this," said police Capt. Michael Gregory.