The suspect in a brutal and apparently random attack of two young boys at a park will face murder charges after both victims died Friday, police said.

Edwin Pellecier and Jesse Ramirez suffered severe head injuries when they were repeatedly bludgeoned Tuesday afternoon, Phoenix police Sgt. Tommy Thompson said. Seven-year-old Jesse died early Friday and his 10-year-old cousin, Edwin, was pronounced dead hours later.

Police arrested Joe Sauceda Gallegos, 36, within hours of the attack on Tuesday.

A first-degree murder charge was added after Jesse's death and a second was planned after Edwin died, Thompson said. He was charged earlier with two counts of child abuse and dangerous crimes against children. Bail was set at $1 million.

Doctors believe the boys were bludgeoned repeatedly with a baseball bat or similar object. Police say they found a bat in Gallegos' home along with clothing that appeared to be bloodstained.

"It was just a brutal, vicious attack that didn't need to happen," Thompson said.

Court records did not list an attorney for Gallegos.

Thompson said Gallegos, who lived nearby, followed the boys to the small community park and attacked them, then walked back to his home. Police don't know a motive.

Police said video from a surveillance camera mounted in front of a house near the park showed the boys walking toward the park, followed a minute later by a man carrying an object that looked like a bat. A neighborhood resident said the man looked like Gallegos.

An uncle of Gallegos, Joe Sauceda, told police he believed Gallegos had been diagnosed as a schizophrenic. The uncle also said Gallegos had told authorities about six months ago that he killed his sons in his attic, but police never found any such victims at the house. Gallegos' sons live with their mother in Colorado and are the same ages of the boys who were attacked.