Crazed Times Square stabber’s brother reveals long struggle with mental health, possible bipolar diagnosis

The crazed knife-wielding woman who stabbed two people near Times Square long struggled with her mental health, but showed no sign she’d go murderously berserk, her stunned brother said Tuesday.

Pamela Cisneros, 49, seemingly lived a normal life in the days before she fatally knifed a woman and seriously wounded a man during a terrifying random attack Monday, said her brother Patrick Peralta, 59.

“She never showed any aggressiveness or being violent. I don’t know what happened,” Peralta, 59, told The Post.

Shocking video shows NYPD cops confront Cisneros, still clutching two knives, after the two attacks near West 41st Street and Seventh Avenue around 4:30 p.m. Monday.

Officers first unsuccessfully used stun guns on her as she started to windmill her arms around, with an arm in each hand, then shot her when she charged them, the video shows.

She died from her wounds at Bellevue Hospital, officials said.

Peralta said he learned about the disturbing incident on the news, initially brushing it off as “typical New York crap.”

He said he couldn’t believe it was his sister, until he saw photographs from the showdown.

Cisneros tried to commit suicide when she was around 19 and had been diagnosed with a mental health issue, Peralta said.

“I think bipolar, but I don’t know what else was going on,” he said, noting she received monthly injections for treatment.

“I think maybe she stopped the injection she was getting and that caused her to act the way she was.”

The last time Peralta saw his troubled sister was in August for their stepfather’s birthday, he said. She regularly visited their mother as well, but recently stopped, he said.

“There was no sign something was wrong,” he said. “Last week she stopped coming to see my mother.

“We called, she said she was fine on Saturday.”