TORONTO -- The man who gunned down 15-year-old Jarvis Montaque in front of his home earlier this month should "man up" and turn himself in to police, two of the Toronto teen's sisters said Tuesday.

Roshea Gunnis broke down in tears as she spoke about her only brother.

"I just wanted to let everybody out there know that my brother was an amazing person and he didn't deserve to be taken away from us," she said.

Tanasha Smith, Montaque's eldest sister, urged any witnesses or anyone else with information to come forward to help police solve his killing, saying it happened for no reason.

She also had some advice for his killer: get a lawyer and go see the police.

"Man up to your responsibilities. Man up to what you have committed," Smith said.

"We all have a chance at life and Jarvis's life was ended. He wasn't given a chance. But this person who committed this crime may or may not have a chance himself at life," she said.

The sisters' emotional plea came as Toronto police announced a new Crime Stoppers campaign to encourage people to report crimes anonymously.

Montaque was shot at close range on Feb. 17 while socializing with friends and family in front of his home in the city's west end. Police say the gunman simply walked away afterwards.

Det. Gary Giroux repeated his appeal for any witnesses to come forward and help investigators solve the killing of Montaque, who was the fourth minor to die in gunfire in the Toronto area this year.

Police have described Montaque as a "good kid" who was living with his family while going to school. The only boy in a family with 10 sisters, he came to Canada from Jamaica two years ago and was not known to police.

Smith said the family is hoping to be able to take her brother's body back to Jamaica. The community must come together if the gun violence is to end, she added.

"Having a gun, it has a lot of power behind that tool," Smith said. "They feel as long as they're holding it ... they're invincible and no one can do anything to them."

"Jarvis wasn't into all of those type of things," added Gunnis. "He never surrounded himself (with) any kind of negativity. He came to Canada with ambition to become a soldier to fight for Canada. He didn't deserve his life taken away from him."

The new campaign will feature posters encouraging people to use Crime Stoppers to report crime without having to disclose their identity. The messages will be distributed throughout the city's police divisions and electronically at local Mac's convenience stores.