Complex sentence: In the midst of helping a customer, Negron suddenly seems to recognize the man and immediately pulls a WWII-era German Luger from under the counter and shoots the man in the chest, killing him instantly.
Split into simpler sentences: In the midst of helping a customer, Negron suddenly seems to recognize the man. He immediately pulls a World War II-era German Luger from under the counter and shoots the man in the chest, killing him instantly.