The remaining perpetrator after the stabbing in Saskatchewan province in Canada was arrested during the night Wednesday to Thursday.
After a couple of hours, he died of self-inflicted injuries.
After a three-day manhunt, the man was arrested when his car ran off the road, AP reports.
Police tracked him down near the town of Rosthern in the province of Saskatchewan after a report that a stolen car was seen being driven by a man armed with a knife.
Bloodiest yet
In Sunday's stabbing, 10 people were stabbed to death and 19 others were injured in the bloodiest knife attack in Canada's modern history.
The perpetrators were two brothers aged 30 and 31.
One of them was found dead already on Sunday shortly after the attack, but the remaining brother was on the run since Sunday.
Long criminal record
That the brothers were able to carry out the act has raised questions in Canada.
The most recently arrested brother has a long criminal record with several convictions for violence and crimes against both persons and property.
Court documents also show that seven years ago he stabbed one of the victims who were killed on Sunday.
The perpetrator must also often have been under the influence of drugs or alcohol when he committed previous crimes.