Ottawa police say a man is facing 37 sex-related charges in connection with four male victims, including one boy who was a patient at a hospice.

They say that charges against 41-year-old Danyiel Walker include aggravated sexual assault, sexual interference with minors, sexual exploitation and threats.

The four alleged victims range in age from six to 24 years old, and police say the alleged crimes span a 15-year period beginning in 2004.

Sources tell CTV Ottawa that one of the alleged victims was a patient with a disability at Roger Neilson House, a palliative care facility for children and youth.

Walker’s son, who died in November 2015 at the age of 11, had cerebral palsy and was a patient there, too.

Sources say that while Walker was not a volunteer at the hospice centre, he had access to the organization, though they could not say how.

Roger Nielson House told CTV Ottawa that it is not prepared to comment on the allegations.

Walker appeared in court on Jan. 31 after being charged with 10 child pornography crimes.

The next day, according to Ottawa police, a victim came forward with allegations of sexual abuse that led to additional charges.

Ottawa police believe that there are more victims and say that more charges could be coming.

Walker was remanded into custody and will make his next court appearance on Feb. 28.

None of the allegations against him have been proven in court.