Complex sentence: Later that evening a white police officer, John Gleason, was manning a checkpoint when he started to chase a black youth into the ghetto; when he caught up with the young man, he shot and wounded him.
Split into simpler sentences: Later that evening a white police officer, John Gleason, was manning a checkpoint when he started to chase a black youth into the ghetto. When he caught up with the young man, he shot and wounded him.