KANSAS CITY, Mo. (AP) — A Missouri police chief who was forced to resign following allegations he assaulted a father who tried to drown his 6-month-old daughter has been sentenced to 18 years in prison for attacking his ex-wife during a domestic dispute, a prosecutor said.

Greg Hallgrimson was sentenced Friday in the case in which authorities say he punched and knocked his ex-wife unconscious in June 2020, the Kansas City Star reported.

Hallgrimson was chief of the Greenwood Police Department when a man walked into the department in December 2018 and said he had just tried to drown his daughter in a retention pond. Hallgrimson and another officer rushed to the icy pond and pulled the unconscious child out of the water. She was rushed to a hospital, where she was treated for severe hypothermia. But prosecutors said that upon completing the rescue mission, Hallgrimson threw the father to the ground back at a police station and punched him in the face.

Hallgrimson was placed on administrative leave shortly after he was accused of assault and resigned in May 2019. Greenwood is about 20 miles southeast of Kansas City. A federal judge subsequently sentenced Hallgrimson, who pleaded guilty to violating the civil rights of the father, to five years of probation.

After Hallgrimson was indicted on a charge of violating the father’s civil rights but before he was sentenced to probation in that case, he hit his wife so hard that she was knocked unconscious, according to authorities.

The ex-wife was worried for her safety and initially told doctors the she broke her nose and fractured her eye socket falling down some stairs, the prosecutor said. Police began investigating about 17 months later. Defense attorneys for Hallgrimson had argued that Hallgrimson was not the initial aggressor because he was slapped first.

In a statement Friday, Prosecuting Attorney Zachary Thompson said the sentence “sent an unmistakable message today that victims of domestic abuse will be heard and supported” in Clay County where the case was prosecuted.