ST PETERSBURG, FL — A man with a machete beheaded another man during a fight Monday, then put the severed head on the hood of a car as neighbors watched, police said.

The suspect, Dennis Roache, 34, was ordered held without bail on a first-degree murder charge. Police said Roache has a history of mental illness.

He was adjusting the mirror so the head, if it were alive, could see itself.

A woman called police after Roache, a former boyfriend, allegedly broke into the home of her current boyfriend, Gregory L. Shannon, 18. Police said Roache cut Shannon several times with the machete, then beheaded him.

Neighbors watched as Roache put the head on the car hood, then tried to arrange a rearview mirror in front of the decapitated head, police said.

"He was adjusting the mirror so the head, if it were alive, could see itself," police spokesman George Kajtsa said.

The woman was not injured.