No new laws are needed. They just have to enforce the ones that already exist.
Posecutors routinely offer plea bargains. For gun crimes, they offer to plea bargain the gun charges away (possession of a restricted/prohibited firearm, use of a firearm in the commission of a crime, pointing a firearm etc etc, for a guilty plea of simple robbery or assault. Then, they get a slap on the wrist and they are soon on the street again, and the Crown, can process these as quickly as they can to get to the next one: good for statistics.
I think it's because the system is overwhelmed, and the Crown cannot deal with the sheer number of gun crime with full trials: not enough money for fully prosecuting gun crimes., except for the most egregious ones.
They should put more money into prosecuting, convicting and keeping these sociopaths away from society.... but it takes money to hire more Crown Prosecutors, Judges, Court time, prisons etc.