I’m not quite sure why some people insist on putting their finger into the trigger guard while manipulating a firearm, perhaps it seems natural, but the trigger is what causes the firing pin or striker to contact the primer on the cartridge and ultimately discharge the bullet. Just two days ago a police officer in Kentucky felt the need to manipulate his firearm in an elevator while holding a box and talking to another person. He shot the wall which caused the bullet to ricochet and hit him in the abdomen. Several things went wrong here, the first of which is don’t manipulate your firearm unless you can give it your full attention or need to do so to stop a threat. The biggest thing that went wrong is that finger went into the trigger guard and contacted the trigger. As you try to holster you generally clench your hand and if a finger is inside the trigger guard you can fire off a round. There was an instructor demonstrating holstering at the range who fired a round into his thigh because he did not keep his finger outside the trigger guard and off the trigger. When handling a firearm you must follow the safety rules and be diligent to ensure your full attention is given to the firearm, muzzle, and keeping your finger outside the trigger guard and off the trigger.