A Cambridge man was arrested after state troopers allegedly found a gun in his car during a motor vehicle stop in Everett, State Police said. Troopers were patrolling Route 99 at about 8 p.m. Tuesday when they saw a man allegedly ignore a traffic signal. They pulled him over and allegedly found a .40-caliber Smith & Wesson handgun in his car, State Police said. David Humberto, 24, is being charged with unlawful possession of a large-capacity firearm, carrying a firearm without a license, unlawful possession of a large-capacity feeding device, and improper storage of a large-capacity firearm.Jacqueline Tempera can be reached at email@example.com. Follow her on twitter @jacktemp.