Man arrested for attempted murder of son in Denver makes first court appearance

Posted at 3:07 PM, January 21, 2022 and last updated 12:41 AM, December 13, 2022

By: Blair Miller

DENVER (KMGH) – The man arrested for investigation of the attempted murder of his 5-year-old son along the Cherry Creek Trail last week confessed to trying to kill his son and was driven by mental health issues, a Denver court heard Thursday at his first appearance.

Michael Ninomiya, 42, was arrested Wednesday for investigation of attempted first-degree murder, attempted first-degree murder – position of trust, attempted child abuse causing death, and child abuse causing serious bodily injury.


On Jan. 12, the Denver Fire Department was called about a 5-year-old boy who had fallen into the water near the trail near South Chester Court and East Cornell Avenue.

Ninomiya called 911, according to a heavily redacted affidavit for his arrest. Firefighters eventually found him and his son in a drainage culvert along the trail and pulled both out of the water.

The boy was taken to Children’s Hospital in critical condition. Ninomiya had a cut to his forehead and was brought to Swedish Hospital. Two days later, Metro Denver Crime Stoppers issued a bulletin asking for any possible witnesses to come forward.

According to the affidavit, the boy’s mother asked Ninomiya that day how the boy was doing after the two went on a walk. But he did not reply, and the mother started receiving calls from Children’s Hospital about her son being in critical condition.

The affidavit said that as of Tuesday, the boy was in critical condition because of fluctuating pressure in his brain.

In court Thursday, Ninomiya’s attorney said he had severe mental health issues and was not accepting treatment for them in the past. The attorney said that after receiving treatment at the hospital, Ninomiya feels immense guilt for what transpired.

The court heard that Ninomiya took steps to appear like the incident was an accident, but also that he had confessed to trying to kill the boy.

The state is expected to finalize formal charges in coming days, prosecutors said.

The defense asked the judge to set a $50,000 cash or surety bond for Ninomiya, while prosecutors asked for a $1 million cash-only bond.

The judge decided to issue a $1 million cash, surety or property bond, which should he post, Ninomiya would be under in-home detention and required to take medication.

This story was originally published Jan. 20, 2022, by KMGH in Denver, an E.W. Scripps Company.