Complex sentence: The officer said he reacted by drawing his weapon in turn, firing at least three shots in defense; as the officer fired, he stumbled backwards and fell to the ground while retreating, all of which was caught on video by the store's security cameras.
Split into simpler sentences: The officer said he reacted by drawing his weapon in turn, firing at least three shots in defense. As the officer fired, he stumbled backwards and fell to the ground while retreating, all of which was caught on video by the store's security cameras.