Nearly two decades after murdering his mother with a shotgun, a 34-year-old man was sentenced to five years in prison Friday for possessing firearms while being prohibited from doing so.

Christian Oberender on Friday pleaded guilty to two counts: possessing firearms both as a felon and after being previously committed as mentally ill and dangerous, according to a release from the Carver County attorney’s office.

Oberender accumulated an arsenal including semi-automatic rifles, an AK-47, a Tommy gun and various shotguns and handguns by lying on applications to possess or purchase firearms.

His sentencing marks the end of a nearly two-year legal process involving an appeal by the Carver County attorney and possible prosecution by the U.S. attorney if the state did not prosecute, according to the release.

Oberender was adjudicated delinquent under extended juvenile jurisdiction for second-degree murder in 1996 and civilly committed in 1998.

Carver County Sheriff Jim Olson, who worked on the 1995 murder, investigated the firearms possession case after receiving a citizen tip, the release said.

Christian Phillip Oberender.

Oberender must serve 40 months of his sentence in prison and 20 months on supervised release, according to the release. Time already served in the Carver County jail will count toward that total.

The 13 guns seized from his home were forfeited, authorities said. He also must pay a $2,000 fine.