Petaluma police have arrested a man on probation after he was found with a gun, ammo, and drugs. Early last Thursday morning, an officer contacted Michael Galli who was walking in the 4000 block of Petaluma Boulevard North. Galli showed to have a Sonoma County warrant issued for his arrest due to a probation violation. He was searched and police found a loaded Smith & Wesson, .38 caliber handgun in his backpack. They also found a Billy club, suspected meth, and drug paraphernalia. Galli was arrested on five charges, including felon in possession of a firearm.