Complex sentence: Crime scene investigators found that about 76 shots were fired in total inside the theater: six shots fired from the shotgun, 65 shots fired from the semi-automatic rifle, and five shots fired from the.40-caliber handgun.
Split into simpler sentences: Crime scene investigators found that about 76 shots were fired in total inside the theater. This comprised of six shots fired from the shotgun, 65 shots fired from the semi-automatic rifle, and five shots fired from the.40-caliber handgun.