Plea terms toughened for Minnesota man whose gun was used by 4-year-old to kill little brother

A new guilty plea agreement was accepted Friday in the case of a southern Minnesota man charged in the death of his 2-year-old boy who was shot by his 4-year-old brother with an unsecured gun.

In April, Martin County District Judge Michael Trushenski tossed out the deal reached a month earlier between County Attorney Taylor McGowan and the defense for 34-year-old Colton Mammenga of Welcome, Minn., in connection with the Oct. 15 shooting of Matthew Alshaikhnasser in a moving pickup truck.

The terms of the initial plea deal called for the dismissal of manslaughter and attempted manslaughter charges and one count of negligent storage of a gun. In exchange, Mammenga agreed to plead guilty to felony child endangerment.

The deal also called for no jail time, no fines and for the plea to be entered under a stay of adjudication, meaning the conviction would have come off his record after adhering to the terms of his probation.

The new agreement, reached this week, now could result in jail time and will remain on Mammenga’s record. It calls for Mammenga to admit to the same charge as before and sets aside any imprisonment. It also caps jail time at 90 days with electronic home monitoring as an option. Mammenga must also serve 500 hours of community service and speaking engagements as previously agreed upon.

McGowan said the judge accepted the new terms at a hearing Friday morning. Sentencing is scheduled for Sept. 6.

In a letter to the judge before the first plea deal was rejected, McGowan explained that “a young child died as the result of an action that was accidental, yet at the same time criminal. Mr. Mammenga is someone who loved that child and is no doubt punishing himself more than the state court could ever do.”

At the time of the shooting, Mammenga was in the pickup truck with the two boys and their mother, who was in a relationship with Mammenga.

A deputy found the pickup outside Fairmont and pulled it over to the shoulder. Mammenga got out of the vehicle holding Matthew, who had a gunshot wound on top of his head.

Mammenga performed CPR before an ambulance crew arrived and took over. He told law enforcement the 4-year-old accidentally shot Matthew while the truck was in motion, and the gun was still in the back seat with the older child. The injured boy was taken by air ambulance to a Rochester hospital, where he died two days later.

Three rifles and ammunition and magazines for those weapons were also seized from the truck by law enforcement, according to court records filed by the Sheriff’s Office.