TECUMSEH – A felony assault charge has been filed against an inmate at the Tecumseh State Correctional Institution regarding one of two incidents where an incorrect door was accidentally opened.

A state Department of Corrections press release says a staff member was assaulted April 8 when an inmate exited his cell after it had been accidentally opened.

Evan Swenson, 29, is also charged with possession of a deadly weapon, which was described as a makeshift tool that could cause a puncture wound.

The incident involving Swenson, who is serving a 20-year sentence for second degree murder in Buffalo County, followed a March 22 assault involving other inmates when a door was accidentally opened.

The corrections department said the prison’s Special Management Unit was placed on modified operations until steps were completed to ensure doors are not accidentally opened.

Corrections Director Scott Frakes said mistakes can lead to bad outcomes in any line of work and it is especially true in corrections.

Prosecutors say Swenson hit the prison officer in the head and torso with his fist. Pepper spray was used to subdue the inmate.