Chester Rusek believed his roommate in a Town of Tonawanda nursing home was stealing from him.

So on a recent Monday morning, Rusek retaliated and repeatedly beat the 86-year-old roommate, Salvatore Trusello, with a 2½-pound magnet as Trusello lay in his bed in Kenwell-DePaul Senior Living Community on Delaware Avenue, police said.

Then, Rusek, 87, who gets around with the use of a walker, shuffled down the hallway and told the attendant to get help.

“He’s going to need medical attention,” Rusek told the attendant, according to police reports. “I just beat his [expletive].”

“I didn’t want to kill him,” Rusek later told police. “I just wanted to get even.”

Rusek was arrested for the Nov. 26 attack and charged with first-degree assault and fourth-degree criminal possession of a weapon, said Town of Tonawanda Detective Lt. Joseph Carosi.

Rusek, who was ordered to undergo a psychiatric evaluation, remains in custody at the Erie County Holding Center in lieu of $10,000 bail.

Trusello, meanwhile, is fighting for his life. He is listed in critical condition in Erie County Medical Center.

“These charges are subject to change if the victim passes away as a result of his injuries,” Carosi said.

The incident between the two octo- generians came to light Friday, after Trusello’s family members reported the attack to WIVB-TV news.

Trusello’s daughter told Channel 4 that her father kept to himself, and she doubted that his roommate just snapped.

“There had to be some warning,” she said. “There had to be some indication. There had to be some history.”

The nursing home declined to comment about the case Friday, citing federal health privacy regulations, but in a prepared statement said that it “cooperated fully with the authorities to assure a positive resolution. The safety and well-being of our residents is always our primary concern.”

“Kenwell is licensed as an adult-care home and follows all regulations pertaining to admission as regulated by the New York State Department of Health,” the statement read.

The attack occurred at about 9:30 a.m. Nov. 26 in the room the two men shared at Kenwell, 3456 Delaware Ave., Carosi said.

The 2½-pound magnet was tied to a string, which Rusek repeatedly swung at Trusello in his bed, Carosi said.

The blows struck Trusello on his head, face, chest and wrist. Trusello also suffered a broken rib, which punctured one of his lungs, police said.

That’s when Rusek walked down the hall and told the attendant to get medical help for Trusello.

When police arrived, Rusek was waiting.

“Hey, where’s your patrol car?” Rusek asked the responding officer, police said.

“Why?” the officer asked.

“Because I know I’m getting arrested for what I did,” Rusek said, according to police reports.

Trusello was semiconscious when police arrived and identified the roommate as his attacker, Carosi said.

“We have no record of these two having any problem,” Carosi said.

It’s unclear what – if anything – was stolen from Rusek, Carosi said. Investigators have not been able to interview the victim, because of the severity of his injuries, the lieutenant added.

In fact, police were stunned that Trusello’s injuries came at the hands of an 87-year-old man. “This is a frail man,” Carosi said of Rusek. “He uses a walker. He does not get around very well at all.”