Just after 10 a.m. on Sunday morning, Brittany Gosney and her boyfriend walked into a police station in Middletown, Ohio, with disturbing news: Gosney’s 6-year-old son, James Hutchinson, was missing. Middletown police immediately began searching, posting pleas for help and images of the red-haired child in black frame glasses.

But Gosney, 29, and her boyfriend, 42-year-old James Hamilton, were lying, police said on Monday.

In fact, Gosney had run over her son in a park days earlier after trying to abandon him there, according to police. Then she and Hamilton allegedly threw his body into the Ohio River.

Gosney was arrested and charged with murder, abuse of a corpse and tampering with evidence, and Hamilton was charged with abuse of a corpse and tampering with evidence. Two other children who lived with the couple have been removed from the home by state authorities, police said.

The case has shaken the city of 48,000 people about 35 miles north of Cincinnati, leaving neighbors and teachers to mourn a boy they described as “joyful.”

“I just wish more people would reach out when they need help with their babies instead of going this route,” Mary Stout, a neighbor, told WKRC. “I just don’t understand. I just don’t understand when it comes to a child.”

Police had few answers on Monday about what allegedly drove Gosney to kill 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.”

On Friday night, two days before Gosney and her boyfriend reported James missing, police said she drove him and her two other children to Rush Run Park in nearby Preble County. In a parking lot near a boat ramp, she allegedly tried to abandon James.

When he tried to get back into the car, she ran him over and left the park, according to court documents reviewed by WKRC. Half an hour later, she allegedly returned and found James dead. She put him back into the car and drove to their home in Middletown.

The next night, Birk said, Gosney and Hamilton drove to a bridge over the Ohio River and threw James’s body over the edge.

When the couple reported James missing on Sunday morning, police were immediately suspicious, Birk said. “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,” he said. “They said he was missing since Saturday night.”

Detectives were quickly called in, and within hours police and Preble County sheriff’s deputies had converged in the park to gather evidence.

By Sunday night, police had called off the search and arrested Hamilton and Gosney, who police said admitted to killing the boy and disposing of his body. Recovery teams began scouring the Ohio River for his remains — work that has been complicated by high water levels and strong currents, Birk said.

On Monday, a judge set a $1 million bond for Gosney, WKRC reported. In court, Gosney told the judge she had a “learning disability” and didn’t understand the proceedings. But Birk disputed that claim in his news conference.

“She seemed to be communicating fine. She understood right from wrong. She understood her constitutional rights,” he said.

On Monday evening, more than 100 people gathered in Middletown to remember James in a vigil at a neighborhood park. His father, Lewis Hutchinson, told reporters his son could light up a room with his presence.

“The whole room could be down in the dumps and he could bring joy to all of them,” he told the Dayton Daily News. “He was really funny, he loved to gives hugs to everyone, he was a great kid.”

Hutchinson said he was still struggling to come to terms with the tragedy.

“I don’t know how to process this,” he told the Daily News. “I want justice for him, that’s what I want.”