Homicide detectives are asking for assistance from anyone who may have seen Toronto's latest murder victim returning home from work on Monday.

William "Billy" Nathanson, 19, died of gunshot wounds in the alley behind his mother's northwest Toronto townhouse at house at 1862 Sheppard Ave. West on Monday night.

"Billy was two days shy of his 20th birthday," Homicide Det.-Sgt. Pauline Gray told reporters on Wednesday. "He became the 55th (murder) victim of 2010."

Investigators say the victim was found at about 10 p.m. Monday. He was taken to Sunnybrook hospital for treatment but was pronounced dead.

Gray said Nathanson was ambushed by two people as he returned home from work. Two men were seen leaving the scene in a dark-coloured four-door sedan.

"The fact that they ambushed him tells me that they know a little about his schedule," Gray said, when asked whether they suspected he was targeted.

She asked anyone who may have been travelling in the Jane Street and Sheppard Avenue area Monday night to contact police.

Gray said Nathanson was wearing a "very distinctive" jacket when he left the clothing store where he worked. She said he left work safely, but wanted to hear from anyone who may have seen him on his way home.

She said it is possible someone may remember seeing Nathanson travelling on foot or by transit shortly before his death.

Reports out Tuesday say Nathanson had been on bail for charges related to an attempted murder from 2009.

Nathanson was involved in a case appearing before the courts, Gray confirmed, but said there was no indication that it had anything to do with his death.

"Nathanson was a good employee," she said. "We have interviewed his bosses, his co-workers and he was reliable and stuck to a pretty tight schedule. He went to school during the day; he worked every night, five nights a week. He would be pretty tight as to when he would be coming and going."

Police described the suspects as black men, both relatively tall, one with light skin.

This isn't the first time violence has touched Nathanson's townhouse complex.

In 2007, 11-year-old Ephraim Brown died from gunshots. He was caught in the crossfire of rival gangs during a family barbecue.

A trial is currently taking place for the men accused of killing Brown.