The lead officer for Regina's anti-gang unit says street gangs in that city are constantly recruiting members, even as the justice system puts some behind bars.

"There's always recruiting going on," Det. Sgt. Rob Weir told CBC News in a recent interview. "It's a situation we always have to be on top of."

Weir helped in the arrest and ultimate conviction of three acknowledged leaders of a Regina gang known as NSK, or the Native Syndicate Killers.

Jacob Worm, his brother Tyrone Worm, and cousin Denny Jimmy were convicted Jan. 30 in the shooting death of a Regina man in a violent home invasion in 2006. Douglas Anderson was shot in the stomach and died. In the same attack several of his family members, also in the home, were beaten.

Jacob Worm will be sentenced for second-degree murder, Tyrone Worm and Denny Jimmy will be sentenced for manslaughter.

Weir said the case presented police with several challenges.

"There was a lot of work put into that investigation," he said. "As well as a lot of work in the last couple of years keeping it going through the court systems."

Weir said it was especially important to ensure witnesses were safe and would testify openly about what they saw.

"Over the course of two years, a lot of things can happen," Weir said. "These people can be transient. We're trying to stay on top of them. Lots of work involved just making sure they're still safe."

'Every time you take one off the street, there will be two or three more recruited' — Det. Sgt. Rob Weir, Regina Police

With the convictions of three high-ranking members of a major Regina gang, Weir said the NSK will be set back but only for a short time.

"Even though we're making arrests and getting convictions on a core group of them, there's still more coming up and filing those roles," Weir said. "Every time you take one off the street, there will be two or three more recruited within the correctional centres," Weir said. "Even out on the streets, it's just a constant thing."

The prison system has revealed itself to be rife with gang culture. In another recent trial, involving gang members inside the Regina Provincial Correctional Centre, officials estimated that the jail was home to 67 active, known gang members from seven or eight criminal organizations.