A pistol can be given as a quest reward:.

The pistol can accept all the normal handgun mods: Luckily, Pistol Ammo is quite easy to get a hold of, namely from the various Punks found in Moresby who are a reliable source of ammo for the weapon. It can take down high health special infected like Thugs and Wrestlers eventually, though it will likely require multiple magazines. It's not the slowest reloading weapon, and it can take down Infected relatively easily, though against Butchers or other high health but fast enemies, it's not as good of a choice if you want to avoid getting hit. They can kill Walkers with roughly 5 shots to the body, and 3 to the head, and with 15 shots in the magazine, it can be used to deal decent damage to a horde of zombies or Infected. They have medium damage, on par roughly with a Revolver but lower than a Heavy Pistol and far less than a Magnum, and medium to high accuracy, allowing you to quite reliably hit zombies from a distance, if not with particularly great accuracy. Pistols are the basic firearm found in the game, and so feature decent stats, if not anything amazing.

Dead island 2 modded weapons