In April, 16-year-old Anne Josette Hill told her family she was going to visit a friend. They haven't seen or heard from her since.

When her family reported her missing, police first believed the girl to be a runaway, and the case was handled as a missing persons case. However, the case quickly became more grim when Hill's white Monte Carlo was discovered  a few days later, abandoned in Edmond.

In May, the case was turned over to homicide investigators.

On Friday, almost 6 months to the day after the Piedmont teen disappeared, another teen girl walked into a police station and told investigators that she was there when Hill was murdered.

Chloe Thomas, 17, was accompanied by her father when she went to Oklahoma City police. He told them that his daughter confessed to involvement in Hill's killing.

Thomas told investigators that she was staying at an Edmond apartment with a friend, 16-year-old Chadd Raymond. The apartment belonged to Raymond's brother, who was in prison at the time. The girl said Raymond's brother's cell phone began to receive text messages from Hill, who was wanting to come buy drugs from him. Thomas says she and Raymond responded to the texts, pretending to be the brother, to lure Hill to the apartment.

When she arrived, says Thomas, the three teens watched a movie together before Hill decided to leave for a party. When she tried to leave, Thomas says, Raymond attacked, choking the girl to death.

Thomas told investigators that she and Raymond took the girl's body to the woods, laid it on the ground, and covered it with leaves and sticks. Her affidavit states that the two then abandoned Hill's car in an Edmond neighborhood.

After Thomas gave her statement, police arrested her and obtained an arrest warrant for Raymond. Both teens were arrested on first degree murder complaints.

Raymond was enrolled as a freshman at Edmond Santa Fe High School, having also attended the district's alternative high school, Boulevard Academy. Thomas had been attending Boulevard Academy, but dropped out just days after Hill was reported missing.

In Oklahoma, teenagers under 18 may be tried as juvenile delinquents, youthful offenders, or adults. Being tried as a youthful offender serves as a middle ground between being adjudicated delinquent, which may not be appropriate for more serious crimes, and being convicted as an adult, which may not be appropriate for all young offenders. Teens are typically tried as youthful offenders for serious and violent crimes such as rape, armed robbery, second degree murder, first degree burglary, and assault with a deadly weapon.

For first degree murder charges, anyone aged 13 and older may be tried as an adult. According to state law, 13- and 14-year-olds charged with murder are tried as adults unless they are certified as youthful offenders. However, older teens aged 15, 16, or 17 charged with first degree murder are tried as adults.