Special weapons in gta online

[therealcamc]

so I was playing in the humane labs heist and I had just completed the EMP setup, when we got back into freemode I realised I had the stun gun and rail gun as well as bz gas and a fire extinguisher, after I had played around with them some guy decided to kill me for no reason and when I re spawned I didn't have the stun gun anymore, the only way I thought I could've got them is I had been in director mode before with my online character and I used the native trainer to 'give all weapons' when I tried again to do it I didn't get the weapons back though. so my question is how can we get the stun gun and other weapons? I think the stun gun is really cool and fun to just mess around with, any help is appreciated and maybe we can find a working method to get these special weapons in gta online! thank you.