They are not used in stickups for the same reason Rolls-Royces are not used as getaway cars.
I wouldn’t use a gun registered in my name and of a type that is relatively rare for the same reason I wouldn’t use a Rolls-Royce with my number plate right there on the back as a getaway car. I don’t want the authorities to have a reason to privilege me as a hypothesis just because Mortimer and I are the only two people registered with that kind of weapon in the entire city.
I wouldn’t use a gun registered in my name and of a type that is relatively rare for the same reason I wouldn’t use a Rolls-Royce with my number plate right there on the back as a getaway car. I don’t want the authorities to have a reason to privilege me as a hypothesis just because Mortimer and I are the only two people registered with that kind of weapon in the entire city.