[Murder Gamemode] [Pointshop]make knife sweps only accessible to the murderer

[djegames]

Hi. I have a murder server and I have downloaded knife sweps to sell them on the pointshop of my server. I wanna make them only available to the murderer.

On the (pointshop) lua file, I already added...
function ITEM:CanPlayerEquip(ply)return ply:GetMurderer()
end

... and ...
function GM:PlayerDeath(ply)
ply:StripWeapon(self.WeaponClass)
end

... but when the murderer wins the game, this player keep the knife since they didn't die...

Any solutions ?