I can't recall the length but anything before a limit of automatically considered a handgun by the RCMP.

That is incorrect. Non-restricted, semi-auto, centre fire rifle and shotgun barrels must be greater than 18.5” and the overall length cannot be less than 26” otherwise the firearm will be classified as restricted which you have to register it under your possession and acquisition license.

Non-restricted - What's included in this class

This class includes any firearm that is neither restricted nor prohibited. Most common rifles and shotguns are non-restricted, but there are exceptions.

Restricted - What's included in this class

• Handguns that are not prohibited firearms

• Firearms that:

1. are not prohibited firearms

2. have a barrel less than 470 mm in length

3. are capable of discharging centre-fire ammunition in a semi-automatic manner

• Firearms designed or adapted to be fired when reduced to a length of less than 660 mm by folding, telescoping or otherwise

• Firearms of any other kind prescribed to be restricted firearms in the Regulations

Prohibited - What's included in this class

• Handguns with barrels equal to or less than 105 mm in length

• Handguns designed or adapted to discharge a 25 or 32 calibre cartridge

1. This does not include handguns for use in international sporting competitions governed by the rules of the International Shooting Union and where the handgun is prescribed to be restricted

• Firearms adapted from a rifle or shotgun, whether by sawing, cutting or any other alteration, and that, as so adapted are:

1. less than 660 mm in length

2. 660 mm or greater in length and has a barrel less than 457 mm in length

• Automatic firearms, whether or not altered to discharge only one projectile with one pressure of the trigger

• A firearm that is not a handgun and that

1. discharges centre-fire ammunition in a semi-automatic manner;

2. was originally designed with a detachable cartridge magazine with a capacity of six cartridges or more; and

3. is designed and manufactured on or after December 15, 2023

• Firearms prescribed to be prohibited firearms in the Regulations (including firearms prescribed by make and model; any firearm with a bore diameter of 20 mm or greater; and any firearm capable of discharging a projectile with a muzzle energy greater than 10,000 joules).

It’s also worth mentioning while the Firearms Reference Table is not technically bound by law, the RCMP and Public Safety essentially treat it like it is, so no matter how much you (illegally) modify a rifle to look like a pistol it’s still was initially designed, manufactured and registered as a rifle.

I'm still suspicious of the PAL plus removed weapons. Is it possible they bought a gun under the table after their weapons were confiscated?

It’s important to note that non-restricted firearms are not registered to PAL licenses like how restricted firearms are (except in Quebec), the only thing noted is the transfer request between seller and buyer, currently the RCMP is claiming that neither the shooter nor mother had these firearms registered to them which can indicate these are non-restricted guns.