How Does a Revolver Work?

The murders were believed to have been committed by someone who had a revolver. How would they know it was a revolver as opposed to some other kind of weapon? They found no shell casings at the scene of the crime. The fact that they did not find those meant probably not a semi-automatic. Revolvers are different. You put your six bullets in when you pull the trigger it fires the bullet and the cylinder spins so it goes to the next bullet and you fire it. Once you've fired all your shots you open the cylinder all the shells are still in the cylinder and you have to remove the shells before you can reload it. So this must have been a revolver and the