In an update to their earlier report about a shooting incident at the Mason City Railroad Yard, officials with the Iowa Division of Criminal Investigation (DCI) said Tuesday, the event began with a case of trespassing. An investigation has determined that on November 29th, Union Pacific Special Agent Louis Miner stopped 30-year old Nathan Lee Olson, of Mason City, for trespassing across Union Pacific property at the intersection of 9th Street NW and Monroe Street. An altercation ensued, during which Olson was shot by the U-P Special Agent. The press release didn’t say whether Olson was armed.

The Union Pacific Railroad employs certified police officers to patrol rail properties across the Midwest. The incident remains under investigation. Olson remains in the care of the Mercy Medical Center of North Iowa. Miner was treated at a hospital Thursday, and then released.

Upon completion, the DCI will forward the results of the investigation to the Cerro Gordo County Attorney’s Office for review. Anyone with information about this incident is asked to contact the Mason City Police Department at (641) 421-3636.