Complex sentence: The alleged shooter was a heavily armed 24-year-old white man wearing a bulletproof vest and gas mask, walked into the emergency exit of Theater Nine, threw a smoke bomb and began to fire.
Split into simpler sentences: The alleged shooter was a heavily armed 24-year-old white man wearing a bulletproof vest and gas mask. Media reported that he walked into the emergency exit of Theater Nine, threw a smoke bomb and began to fire.