Not only are murdering people with guns illegal, so are guns themselves regulated wrt possesion; ie the mechanism is regulated.
In what sense is a call to SWAT regulated?
In what sense is a call to SWAT regulated?
Guns, cars explosives etc are things, and it is possible to regulate their possession wrt individuals that may misuse them.
A call to the police is a service, and is not the same kind of thing since anyone might witness a crime and need to call the police, even unreliable individuals; whereas few people need explosives (esp without a demonstrable need or credentials), and depriving an unreliable individual of e.g guns or a car, is unlikely to be as harmful to third-parties as limiting access to the services of the police.