Toronto police have charged six teens with first-degree murder in connection with the torture and stabbing death of 17-year-old Omar Wellington last summer, bringing some relief to the victim's mother.

The accused, aged between 14 and 17, were arrested earlier this week and have appeared in court. They cannot be named under the Youth Criminal Justice Act.

Wellington was swarmed and beaten by a large group of people on July 14 near 61 Grenoble Dr., a housing complex in the Flemingdon Park area.

He was forced to strip to his underwear before being beaten for hours in broad daylight as possibly dozens of people watched in horror, police said. Wellington was then stabbed in the neck and left for dead.

His body was found in a wooded area of Flemingdon Park the next night. An autopsy concluded he died from "a multitude of stab wounds to the neck."

Police said the motive behind the killing was revenge, but didn't elaborate.

Det. Scott Spratt told reporters the case had "hallmarks of gang activity."

"All six people live in the same neighbourhood and there was a connection with Omar to that neighbourhood," Spratt said at a news conference on Friday.

Detectives were frustrated in their investigation as residents who watched the beating or had information failed to come forward. Police believe they feared retaliation from the accused.

Investigators turned to the popular video-sharing website YouTube.com last month, posting a video and showing a possible suspect and the knife they believe was used in the grisly murder.

Police said comments posted on the website helped in their investigation.

Shortly after the charges were announced, Omar's mother Joy told CTV's Karlene Nation she feels some closure, but is still haunted by the murder.

"After I saw Omar at the funeral home and the multiple stab wounds ... and his face smashed, that picture has not left my mind," Joy said.

She said the arrests should be a warning to those involved in gang activity.

"The arrests send a strong message to all the communities that has gang members that ... you're not untouchable," Joy said.

""The end result with that kind of life is inevitable -- you will kill someone or be killed, so leave this type of life alone."

Anyone who may have more information about the case is asked to contact Det. Sgt. Dean Burks or Det. Scott Spratt of the Homicide Squad at 416-808-7400, or Crime Stoppers anonymously at 416-222-TIPS (8477).

With a report from CTV's Jim Junkin