Police found a young man tied up inside suspected serial killer Bruce McArthur’s apartment on the day they burst in and arrested him, CTV News has learned.

Police were surveilling McArthur when they saw the young man enter his home on Jan. 18, prompting them to go in after him out of concern for his safety, CTV News has independently confirmed. The man was freed from his bonds and was not injured.

McArthur, 66, has been charged with five counts of first-degree murder in what police have characterized as an alleged serial killer situation. Police revealed Monday that skeletal remains had been found inside large planters at a home in Toronto, where McArthur stored supplies used for his landscaping business.

The suspect is charged in connection with the deaths of Selim Esen, 44, Andrew Kinsman, 49, Majeed Kayhan, 58, Soroush Mahmudi, 50, and Dean Lisowick, either 43 or 44. Esen, Kinsman, Kayhan and Mahmudi were each reported missing at some point over the last eight years. Several of the victims were known to be part of Toronto’s gay village, in the neighbourhood of Church Street and Wellesley Street.

Investigators believe there may be more victims, and are scouring approximately 30 properties linked to McArthur.