The Ontario Special Investigations Unit (SIU) says it is going to probe the involvement of two officers in an arrest after a Saturday night stabbing spree in east Hamilton.

A 27-year-old male suspect sustained a broken ankle after a foot chase with police outside an apartment building in the city's Parkdale neighbourhood. 

The pursuit followed a stabbing spree that sent four residents of the apartment complex at 221 Melvin Ave. to hospital. According to witnesses, a man burst into at least two apartments, attacking a mother and her adult son on the eighth floor and a husband and wife on the main level.

Paramedics took four victims plus the suspect to hospital with non-life-threatening injuries.

SIU spokeswoman Jasbir Brar says the provincial probe will focus on the role two officers played in the confrontation. The SIU will also call on at least eight other officers who witnessed the chase to provide testimony.

The SIU is called in any time police are involved in an incident in which someone is severely injured, dies or alleges sexual assault. It can lay charges if officers are found to have used excessive force in interactions with members of the public.

Saturday night’s violent rampage started just before 10 p.m. on Saturday, police say.

The suspect allegedly ran out of the building and was then spotted by police.

A resident of the complex’s fifth floor, who asked not to be named, says she saw the chase. A man, she said, ran up the building’s fire escape to a building next door in an attempt to evade officers.

“He went up on the balcony on the building behind the pizza place,” said the woman, who refused to give her name. “He was trying to kick in the door to get in there.”

The man failed to break in, she said, and police yelled at him about three times to drop his weapon.

“They kept asking him, 'Please drop the knife. Drop the knife. You have nowhere to go.' "

Then, the woman said, she heard three or four shots from what sounded like a Taser, followed by a voice yelling "'If you don’t drop the knife, we’re going to have to Tase you again.' "