I saw a similar mod on liberty-city.ru and tried to download. It didn't work and I decided to make my own.
Result:
Random appearance (only in Los Santos)
The chance of spawn underground is close to zero (When I first started making the script, it was 2 out of three)
The chance of departure is known only to God
Random skin
Shotgun and 9mm pistol with random number of bullets
Random possession of weapons.
Activation: automatically.
(You need a clean main. scm, i.e. no missions.)