Toronto police’s homicide unit is investigating after a man was killed in a shooting in Scarborough Sunday evening.

Emergency crews were called to an apartment building on Victoria Park Avenue, north of Sheppard Avenue East, just before 6:30 p.m. for unknown trouble.

Upon arrival, officers located a man with at least one gunshot wound in the lobby of the building, Toronto police Duty Insp. Paul Rinkoff said.

The victim was taken to a hospital with critical injuries.

Rinkoff said another man suffering from multiple gunshot wounds was located on the ninth floor of the building. The man was taken to a hospital in life-threatening condition.

He was later pronounced dead.

The Forensic Identification Unit believes the shooting happened on the ninth floor of the building, Rinkoff said.

“This is a complex scene. It involves multiple areas of the building,” he said.

“We’re not sure in terms of the sequence of the events, and that will form part of the investigation," he said.

It is unknown at this time if both victims resided in the building.

“Their relationship is the focus of the investigation of the homicide unit,” Rinkoff said.

No suspect information has been released at this time, but Rinkoff said they believe there are outstanding suspects.

He said there is video surveillance in the building, and police will be reviewing that as part of the investigation.

Police were also looking at some vehicles that are in the building’s parking lot.

“We’re appealing to the public, and anyone who may live in this building may have seen or heard anything around 6:30 p.m. please contact the homicide unit, or if you prefer to remain anonymous, please contact Crime Stoppers,” Rinkoff said.