St. Louis, Missouri (CNN) A person is in custody in connection with the death of a 7-year-old boy who was fatally shot this week, St. Louis police Lt. Col. Rochelle Jones said Wednesday.

Police provided no further details.

Xavier Usanga was shot and killed Monday while he and his sisters played in the backyard of their home in the city's Hyde Park neighborhood, police said.

One of his sisters and her friend were grazed, Xavier's father, Ifiok Usanga, told CNN in an interview Wednesday.

Two men were shooting at each other in the street when the child became another innocent victim of gun violence, the boy's mother said.

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