Something seemed wrong with Bernard Allen as he went to the register and asked for a butcher's knife. Employees at the store noted Allen was acting strangely, though nobody stopped him as he walked out and into the adjoining shopping mall with a new eight-inch blade in hand.

Minutes later, a man was dead. Issaruh Jackson, 31, of Tempe, had the misfortune of bumping into Allen in the Fiesta Mall food court restroom on Monday. When he turned around, police said, Allen took out the butcher knife and thrust it into his back.

Police said Tuesday that Allen, 25, admitted to the fatal stabbing and told authorities he suffers from Schizophrenia. Police said Allen also admitted to attacking another man, Lathaniel Clinton Brown, 22, with a pocket knife on Sunday at a Macy's store in the same mall.

Mesa Police Chief George Gascon said the attacks appear to be random. In both cases, Allen told authorities he simply didn't like the way the other men treated him.

"You ... disrespected me," he said while attacking Brown, according to court records.

Allen was booked into jail on a first-degree murder charge and a charge of aggravated assault. He made an initial appearance Tuesday and was ordered held in lieu of $500,000 bond. The public defender's office was appointed to represent him, but no lawyer has yet been assigned.

Brown is recovering from wounds to his neck and back and identified Allen from a photo lineup, court documents said.

Allen is a convicted felon with a history of mental illness who spent six years in prison and was released about two years ago, Gascon said.

According to the documents released Tuesday, Brown was in the store Sunday when Allen walked past him and they made eye contact. After he passed, Allen turned around, grabbed Brown by the neck, and stabbed him in the throat with a small pocket knife, authorities said.

The court documents said that Allen visited his doctor morning Monday before going to the mall again. He paid $41.60 for an 8-inch butcher knife at a mall store, took it out of its packaging, and walked into the mall bathroom. As Jackson stood at a urinal, Allen walked up behind him and stabbed him once in the back.

He was spotted by several witnesses walking through the mall with the bloody knife in his hand, and police received several 911 calls, the documents show. He was apprehended minutes after the calls, outside the mall.

Jackson was found on the restroom floor and died before medical aid could arrive.