OXON HILL, Md. (AP) — Prince George’s County police say a man stabbed his girlfriend’s two teenage sons when they tried to protect her from him. One son, a 14-year-old, was killed.

Officers called to the Oxon Hill apartment early Monday found 14-year-old Keyshaun Mason and his 18-year-old brother suffering from stab wounds.

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Authorities say 48-year-old Sean Crawford, the live-in boyfriend, had been arguing with her, and Mason and his brother tried to help her.

Police say Crawford grabbed a kitchen knife and barricaded himself and the teens’ mother in a bedroom. Officers say when the youths forced their way in, Crawford stabbed Mason in the chest and the other brother in the shoulder.

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Authorities say Mason died at Children’s Hospital. The other brother was taken to another hospital.

Crawford is charged with murder.

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