An 11-year-old boy left home alone with his younger sister in north St. Louis County, Missouri, shot to death a 16-year-old boy who had barged into the house, police said on Friday.
But two people in the neighborhood told the St. Louis Post-Dispatch newspaper that the younger boy was the attacker.
St. Louis County police said in a statement the teenager and another person unsuccessfully tried to enter the house twice on Thursday, and entered through the front door on a third attempt.
The 11-year-old child shot to death the 16-year-old boy with a handgun as the older boy entered the home, St. Louis County police spokesman Sergeant Brian Schellman said in an email. The teenager was shot in the head, police said.
The second person fled after the shooting and was later taken into custody for questioning, Schellman said.
The mother of the 11-year-old boy and the 4-year-old girl, who was not home when the shooting occurred, is cooperating with investigators, police said.
Schellman said the 11-year-old boy was questioned, but he declined to say what the boy told investigators, including whether he indicated he was acting in self-defense.
The St. Louis Post-Dispatch quoted Donna Jackson, 45, who lives across the street from the house where the shooting occurred, as saying she saw the 11-year-old boy shoot the teenager in the head as the two were talking near the home's front door. "It was not a break-in," she told the paper.
Jazmyne Clark, 18, a neighbor who lives two doors down said the teenager might have been trying to sell the 11-year-old boy a phone, according to the newspaper. "He wasn't breaking in at all. He was just trying to sell him his phone," Clark told the paper.
St. Louis County police said they were continuing the investigation.