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.
"The bullet went through my son's throat and then grazed my daughter's elbow," Dawn Usanga told CNN affiliate KTVI.
An 18-year old was also critically wounded during the summer night gun battle, according to Major Mary Warnecke, deputy commander of investigative services for the St. Louis Metro Police Department.
Xavier was scheduled to start second grade at Clay Elementary on Tuesday, his mother told KTVI.
Mourners attended a vigil for Xavier on Wednesday night. There were flowers and candles and action figures of Captain America and Iron Man.
"The people in the community, everybody knew my son. He was the boy who always smiled," Xavier's mother old CNN affiliate KMOV before the vigil. "He would run up and give you a hug."
"Hopefully, somebody will learn that there are consequences to your actions," she said.
Xavier's sister, Angel, told CNN her brother was "a happy baby, always happy."
His father said Xavier asked him to fix his bike on the day he was shot.
"I didn't fix it that day, and now he's gone," he said, looking off in the distance.