Toronto Police may have saved the life of a man who was “tied up” on a bed in accused serial killer Bruce McArthur’s apartment at the time they arrested him, the Toronto Sun has learned.

Police officers, who had McArthur under surveillance around 10:25 a.m. on Jan. 18, did not take any chances when they saw a “young man” enter McArthur’s 19th-floor Thorncliffe Park apartment.

“They had to make a decision,” said a police source.

The decision was to go and arrest local landscaper McArthur, 66, who now faces five charges of first-degree murder, on suspicion of killing Andrew Kinsman and Selim Esen.

“They kicked down the door,” said a source. “They stormed in and arrested McArthur.”