An 18-year-old Toronto man accused in the shooting death of Rizwaan Aboobakar Wadee at an after-prom party in a rented Whitchurch-Stouffville mansion last week surrendered to police on Wednesday night.

Investigators believe that Wadee, who is also 18, was shot to death inside a mansion at 6336 Bloomington Road at about 3:45 a.m. on May 3, in the midst of an after-prom party at the mansion that drew hundreds of teenagers from across the GTA.

York Regional Police Insp. Thai Truong said that when officers arrived at the scene about 20 minutes later, they located Wadee’s lifeless body inside the home, but the hundreds of kids had all fled.

“Not a single person that we know about tried to assist Mr. Wadee or stayed on scene.”

Wadee was a student at Maple High School in Vaughan.

At about 4:30 a.m. that morning, homeowners in the Bethesda Side Road and Ninth Line area, about three kilometres south of the mansion where Wadee was killed, reported seeing two males in the area behaving suspiciously.

Patrol officers found the two males about an hour later hiding in a wooded area.

Truong said the males, a 16 and 17-year-old, both from Toronto, were each found allegedly carrying at least one handgun each.

“The males were trying to get a taxi or a ride out of the area.”

They were charged with a raft of firearm offences on May 3 and on Thursday were charged in relation to Wadee’s death.

Troung said the 16-year-old has been charged with one count of accessory after the fact to murder and the 17-year-old faces one count of first-degree murder.

Neither male can be identified per the terms of the Youth Criminal Justice Act.

On Wednesday, investigators identified a third suspect in Wadee’s killing as 18-year-old Jahdea Paterson.

Troung said he surrendered to police late on Wednesday night and is expected to appear in court in Newmarket on Thursday.

“We don’t have any info that the victim knew the three charged for that incident prior to that evening,” Troung said.

Investigators believe the three accused arrived at the mansion at about 12:30 a.m. that morning, in the company of three to five other youths who were invited to attend.

Troung said police are looking to speak with anyone who witnessed the accused at the party after that time. They are also looking for people who took photos or video that night to upload them to police.

“Everybody has photos, they’re taking selfies, they’re taking videos — we know those images are out there,” he said.

But so far, only one video from that evening has been sent to police.

Truong said it’s imperative police get their hands on more images and video from that evening, as well as eyewitnesses.

“We believe there were individuals who saw the deceased after he was shot.”

Investigators have set up a dedicated web portal for witness images and video.