The longer that Anthony Spencer’s friends hold back information from police, the longer they will have to live in fear, the slain man’s sister said Thursday.

Susan Spencer said the people who witnessed her brother's shooting will always be subject to threats from the person who is responsible for his death.

"He’s going to have to watch you and continually threaten you for the rest of your life," Spencer said, while speaking with Metro Morning host Matt Galloway on Thursday.

"You’re going to be looking over your shoulder for this one person."

Police have revealed that Anthony Spencer was shot inside a Brimley Road recording studio before his friends dropped him at a Scarborough hospital last Saturday.

Those same friends left the hospital without speaking to police, while the 23-year-old aspiring rapper quickly succumbed to his injuries.

When police tracked down Spencer’s friends, they were not forthcoming with investigators.

A few days later, Susan Spencer joined police in making a public appeal for those friends to be fully upfront about what they know.

mi-brimley-studio-location-cbc

A Toronto police cruiser sits outside the building on Brimley Road where investigators say Anthony Spencer was shot. (CBC)

Spencer said that her brother has left behind a family that misses him, as well as a young daughter.

She also said his surviving friends should think about her family when they are refusing to co-operate with police.

"If you are a true friend of Anthony Spencer … you know you owe him," she said.

"You owe him … and you’re going to have to live with that for the rest of your lives."

Police have said they are probing the possibility that Anthony Spencer may have offended local gangs with his music.

But Det. Sgt. Gary Giroux has said there is no indication that Spencer was a part of a criminal organization.