Police arrested a Tennessee man after a 3-year-old allegedly used the man’s gun to fatally shoot his 1-year-old daughter.

Details were not immediately clear. The shooting took place Friday morning in southeast Memphis, WMCA reported. Shawn Moore, 25, was at the apartment of the mother of his 1-year-old daughter, Robbin Keefer (spelled Robin by some news outlets). Moore helped her put the infant to sleep, then allegedly left a handgun within reach of the bed. He forgot it there and left the room, police said.

Robbin’s 3-year-old sibling allegedly found the gun, picked it up and shot the infant. Unidentified witnesses heard the gunshots and found the child wounded, the Associated Press reported. The 3-year-old’s relationship with Moore is unclear.

Moore then allegedly grabbed the gun and fled the scene. Police later found Robbin lying in a bedroom with an apparent gunshot wound to the head. She was rushed to Le Bonheur Children’s Hospital, where she later died.

Moore turned himself in to police later that evening. He was booked into Shelby County Jail about 11 p.m. local time Friday, according to online records.

“It was determined that Robin Keefer was actually shot by her 3-year-old sibling with Moore’s firearm,” police told the Commercial Appeal.

On Saturday, police charged Moore with criminally negligent homicide, being a felon with a handgun and tampering with evidence. Moore was previously charged with domestic assault in 2014 and 2015, but both cases were dismissed for lack of prosecution, the Commercial Appeal reported.

Robbin’s family was still reeling from her sudden death over the weekend.

“She was a sweet baby,” her aunt, Wanda Keefer, told WREG. “She was always smiling. Never cried too much unless she was hungry.”

“My heart just dropped,” Keefer added to the Commercial Appeal. “I just fell on the table. My heart just dropped.”

Moore’s arraignment is scheduled for Monday morning.

A recent study published in the journal Pediatrics found that 5,790 children, on average, receive medical treatment in an emergency room from a gun-related injury each year. About 21 percent of those injuries are unintentional.

From 2012 to 2014, an average of 1,297 died each year from gun-related injuries, the study found.

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