PHILADELPHIA—A boy and his father were killed and the boy's mother was seriously injured in what police are calling a murder-suicide in northeast Philadelphia.

Chief Inspector Scott Small said 10-year-old Jake Harkins Jr. was found dead in his bed early Friday and 48-year-old Jake Harkins Sr. was dead on the floor next to him with a gunshot wound that appeared to be self-inflicted.

The boy's mother, 41-year-old Jessica Harkins, was shot twice in the back of the head but survived and was able to speak with investigators in the hospital. She was reported in stable condition.

Police say a 14-year-old daughter locked herself in her room and called police when a violent argument erupted between her parents. She was uninjured.