Mother admits killing six-year-old son and dumping weighted body in river

Brittany Gosney faces 15 years to life in prison

Brittany Gosney, 29, pleaded guilty to killing one of her children and abandoning two others in February. (Butler CountyJail)

A mother in Ohio has pleaded guilty to killing one of her children and abandoning two others.

Brittany Gosney, 29, of Middletown, Ohio, pleaded guilty to murder and two felony counts of child endangerment on Monday as part of a plea deal.

In February she killed her six-year-old son, James Hutchinson, reportedly after attempting to abandon all three of her children in a park. Police believe James tried to get back into her car as she drove away but was dragged before hitting his head and suffering a fatal injury.

His body has not been recovered.

Gosney initially tried to plead insanity, but her claim was rejected following a psychological examination. Originally she faced 16 charges which included kidnapping in connection to her abandonment of her children. Her two other children, aged seven and nine, survived the incident.

According to a police report, James apparently tried to grab onto the car's handle, but fell as his mother tried to speed away.

Gosney left the park where she had abandoned the children, but returned about 40 minutes later. She found the children still at the spot where she left them, and also discovered that James had died.

She then returned to the family's home.

Gosney and her boyfriend, James Hamilton, 43, kept James' body in a spare bedroom for two days before they weighed it down with a concrete block and dumped him into the Ohio River.

The woman said her boyfriend pressured her to abandon her children back in February.

The boy’s body has not yet been recovered, partially due to flooding in the region. Several attempts to recover his remains have been launched but have been unsuccessful.

"We are still actively searching for James," Middletown spokeswoman Shelby Quinlivan told The Enquirer on Monday.

She said that search efforts would continue later this week if conditions allow.

Gosney will face 15 years to life in prison at her sentencing hearing on 13 September.

Mr Hamilton is also facing kidnapping charges and charges stemming from gross abuse of a corpse.

He has pleaded not guilty and is being held on a $750,000 bond. He will appear in court again later this month.