A  Martin County man faces charges including second-degree manslaughter, child endangerment and negligent storage of a loaded firearm in connection with the fatal shooting of a 2-year-old boy by another child earlier this month.

33-year-old Colton Mammenga of Welcome was charged Thursday in Martin County District Court.

The charges stem from the death of Matthew Alshaikhnasser. Authorities said he was fatally shot by his 4-year-old brother on Oct. 15 after the older boy found a loaded handgun while the two children were left alone for a few minutes in a pickup truck.

Matthew died two days later.

The criminal complaint alleges that gun belonged to Mammenga, identified in court documents as the boyfriend of the children’s mother.

Mammenga allegedly admitted to investigators that he left the loaded firearm in the passenger-side door pocket while he and the children’s mother went back inside their house for a few minutes to retrieve a few items, leaving the children in the truck.

The children’s mother told investigators “that after she retrieved the items she buckled both of the children in and did not see the gun. After departing, she heard a loud ‘boom’ as she was driving,” the complaint states.

She pulled the truck over, and said Mammenga started administering CPR to Matthew as they drove toward the hospital in Fairmont. They were intercepted by first responders who took over care for the child.

Mammenga allegedly told investigators he didn’t notice the handgun was missing until after the shooting. Deputies who searched the vehicle reported finding ammunition scattered about the inside of the truck. Court filings also indicate deputies found other firearms in the vehicle.

Mammenga is due to make his first court appearance on Nov. 7.