Is It a Semi-Auto or a Bolt Action Type Gun?

He says that he held his hand over the breach of the gun to catch the shell. Is that what a breach is? He must have manually done it and grabbed this empty cartridge case versus a semi auto, which would immediately be ejecting the cartridge case out. I think there'd be no way that he'd be able to fire at Mary Louise kill her and he'd catch the cartridge case at the same time of committing that homicide.