RUSSELLVILLE, Ark. — A 15-year-old accused of fatally shooting his older sister as she slept at their family's rural Arkansas home has pleaded guilty to second-degree murder.

A judge on Wednesday sentenced Colton Harvey to 45 years in prison. He was charged as an adult in the shooting death of Candace Harvey. Prosecutors say she was shot three times in the head while she slept.

Prosecutors initially charged the teen with first-degree murder after authorities said he showed up at a sheriff's office in January and confessed to killing the 16-year-old.

The sheriff said the boy seemed remorseful and had tears in his eyes when he turned himself in.

Details in the case were scarce after the judge barred lawyers from talking about it publicly.