A man who has been in hospital under police guard since a shooting in Calgary's Chinatown has been charged with four counts of attempted murder.

Shaun Roberts, 24, was arrested on his release from hospital Tuesday, police said. He also faces four counts of discharging a firearm with intent to endanger life.

Roberts is well-known to the Calgary police organized crime section and gang enforcement team, said acting Staff Sgt. Gord Eiriksson on Wednesday.

"He was under guard not only because we were anticipating laying charges as soon as possible but also because Mr. Roberts is a target," he explained. "If Mr. Roberts was left unattended at the hospital, that would provide opportunity for perhaps some other person to attend the hospital and execute him."

Last month, Roberts testified at an immigration hearing in support of his friend and suspected gangster, Tran Trong Nghi Nguyen, 26, who goes by the name Jackie Tran.

Police had arrested Tran for allegedly breaking his curfew, but immigration officials ruled it was possible that an officer saw Roberts, and not Tran, in a vehicle. Tran is a convicted drug trafficker who has been in the headlines recently as he continues to fight a deportation order issued four years ago.

Roberts is now the fifth man arrested in connection with the Nov. 16 shooting.

Shooting erupted between rival gangs, say police

Four men, aged 17 to 31, were charged last month with four counts each of attempted murder and causing bodily harm with intent. One of them, Daniel Landry, is also a known associate of Tran, said police.

The incident at about 1:30 a.m. by the intersection of Centre Street and Second Avenue South involved two well-known rival gangs, say police. Investigators believe numerous shots were exchanged between two vehicles.

'If you don't want to see your child die in the next short period of time because of this ongoing gang feud, then we encourage you to come forward and talk to us.'—Acting Staff Sgt. Gord Eiriksson, Calgary Police Service

When police arrived, they found one car riddled with at least 17 bullet holes, and two injured victims inside, one of whom was wearing a bulletproof vest.

The second vehicle, which fled the scene, was tracked down by police in the community of Citadel. Inside, they found one man with a gunshot wound to the head, and took him to hospital, investigators revealed Monday.

Police arrested the other three occupants.

While police were at the hospital, two men also arrived with gunshot wounds. Investigators said they believe the pair had been in the bullet-riddled vehicle.

The police have received calls from family of gang members over the last several days asking for help, said Eiriksson.

"If you are a friend, an associate, a girlfriend, surely at this point you must be concerned," he said, urging others to come forward.

"If you don't want to see your child die in the next short period of time because of this ongoing gang feud, then we encourage you to come forward and talk to us, and we'll do whatever we can to help not only you, but [also] the people you care about."