Ohio Police discovered that a mother had killed her son after lying to authorities and reporting him as missing.

The Washington Post reports that Brittany Gosney and her boyfriend, James Hamilton, went to a Middletown, Ohio police station on Sunday morning to tell them she couldn’t find her 6-year-old son, James Hutchinson. Officers quickly began looking for the boy, sharing information and photos of him.

Investigators soon found out the 29-year-old mother’s story wasn’t true. Gosney had actually run her son over with her car in a park a few days before, after trying to leave him there. He died from the injuries to his body, and Gosney and Hamilton later dumped his body in the Ohio River.

Gosney has since been charged with murder, abuse of a corpse, and tampering with evidence, while Hamilton is facing charges of abuse of a corpse and tampering with evidence. The two other children who lived at the couple’s home have been taken by state authorities.

It’s still unclear why Gosney killed her son. “The mother is not showing much remorse at this time. But she has confessed to doing this,” Middletown Police Chief David Birk said at a news conference. “She’s not really saying what the motive was.”

Police said Gosney and her boyfriend drove all three children to Rush Run Park, where she allegedly attempted to abandon James. He tried getting back into the car, so she ran him over and left him there. When she returned to the area 30 minutes later and found James dead, she put him in the car and drove home. The next night, Gosney and Hamilton purportedly drove to a bridge overlooking the Ohio River and tossed James’ body into the water.

The police thought the situation was suspicious when the couple took so long to file a report. “It was a little unusual because usually when you have a missing child, the first thing you do as parents is to contact the police,” Birk said. “They said he was missing since Saturday night.”

The police first went to the park to gather evidence but discontinued the search and ended up arresting Hamilton and Gosney. When the couple confessed to the murder and disposal of his body, authorities went to look for his remains in the river.

Gosney now has a $1 million bond. “I don’t know how to process this,” James’ father Lewis Hutchinson told the Dayton Daily News. “I want justice for him, that’s what I want.