Licence To Kill is a custom Pistol.
The Licence to Kill is the Custom version of the P99 silencer Pistol. It does 50% more damage when it's a headshot. That way it makes up for the low impact.
Doing headshot is not a problem because it has the best accuracy of all pistols. It still has very low fire rate. The Name license to kill is a reference to the 1989 James Bond Movie, License to Kill.