Complex sentence: He goes to Nola's building and gains entry into the apartment of her neighbor, Mrs. Eastby, who he shoots and kills and then stages a burglary by ransacking the rooms and stealing jewelry and drugs.
Split into simpler sentences: He goes to Nola's building and gains entry into the apartment of her neighbor, Mrs. Eastby. He shoots and kills her, then stages a burglary by ransacking the room and stealing some jewelry and drugs.