Hundreds of mourners attended the funeral of aspiring photographer Dylan Ellis, who was murdered alongside best friend Oliver Martin while they sat in a parked SUV on Friday.

Friends and family gathered at Rosedale United Church on Wednesday for the service. They described Ellis as a "caring" and "generous" person.

"It's heartbreaking," Gage Love, Ellis' former teacher, said of the loss. "You can't imagine how heartbreaking it is."

Some have discussed putting up a reward to encourage witnesses to come forward with information that could lead to the men's killer.

Toronto police are considering making a YouTube video to appeal for tips, The Globe and Mail reported Wednesday. However, the video won't be completed until detectives finish examining surveillance footage from cameras throughout the neighbourhood.

Police say the best clue they have received so far is that a man was seen racing from the scene on a bicycle.

The victims, both 25, had just finished watching an NBA game at a friend's house when they were shot in the front seat of Ellis' parked Range Rover. Martin's girlfriend was in the back seat but wasn't injured.

Police have ruled out carjacking and drugs as motives, but say the men may have been involved in a verbal exchange with their killer that fuelled the incident.

Investigators are encouraging area residents to come forward with anything they remember about the night of the murders.

The funeral service for Martin will take place on Thursday.

With a report from CTV Toronto's John Musselman