The stake out began at four-thirty pm on October 23 last year, and started because of a tip-off. Two hours later a man was shot with bullets which could later be traced to the suspect’s weapon, according to local newspaper Sydsvenskan.

Mangs later returned to his apartment, and upon leaving again shortly thereafter, he was followed by the police.

One reason why the police waited to arrest the suspect was that they feared he would get rid of the weapon, which was a decisive piece of evidence.

“We waited. According to a tip we’d received, he’d hidden the weapon outdoors. If we’d gone into the apartment and not found a weapon we would have been screwed,” Börje Sjöholm, operative head of the police investigation, said to Sydsvenskan.

The tip which sparked the investigation and the arrest of Peter Mangs was tracked by the police to one of Malmö municipality’s computers. A friend of Mangs, living in a municipally owned home, told the police what he’d heard him say about the murders.