Const. Paul Davis said police have determined the man who died in a crash on Wednesday in St. John's was involved in a stabbing the preceding day. (CBC)

Police in St. John's said Thursday that a man killed in a car crash early Wednesday is believed to have been the perpetrator of a stabbing earlier this week.

A Mount Pearl resident died when his southbound car crashed into a concrete pole near the intersection of Columbus Drive and Canada Drive in St. John's.

The RNC, which closed the intersection temporarily on Thursday to continue its investigation, said the crash victim is the same man believed to have committed a daylight stabbing in Portugal Cove-St. Philip's.

On Tuesday afternoon, a 64-year-old man in that town was stabbed after he opened his front door.

"We may never know why this accident occurred, and we may never know why this assault occurred on Tuesday," Const. Paul Davis said.

A southbound car on Columbus Drive smashed into this pole early Wednesday morning. (CBC)

Davis said the stabbing victim had never met the perpetrator, and that the assault appears to have been unprovoked.

"He didn't know him at all, but we've been able to, as a result of the investigation, determine that this is the person responsible," said Davis.

Police have also found no links connecting the crash victim to other residents of Portugal Cove-St. Philip's.

Davis said the knife used in Tuesday's stabbing had broken, with part of the knife left at the scene.

Police said investigators found the other part of the knife inside the smashed car.

"We believe the person's mental health was a factor involved in the assault, and may also have been a factor involved in this accident," Davis told reporters Thursday.