Police are investigating a shooting at a Southeast Side apartment complex that killed two people and wounded two others. Officers responded about 6:30 a.m. Sunday to the reported shooting at the apartments on Montrose near Russi Street. They found a man and woman shot to death inside an apartment. They also found a wounded woman who said the shooting had happened in her apartment as the result of an argument. A man with a serious gunshot wound had fled across the street. Police believe drugs may be involved.