The individual responsible for the tragic shooting at a Minneapolis church, which resulted in the death of two children and injuries to 21 others during a Catholic school Mass, legally acquired a firearm just four days prior, as revealed by a local gun shop owner.

Robin Westman initiated gunfire during a school-wide Mass held at Annunciation Catholic Church on August 27, around 8:30 a.m., by shooting through the stained-glass windows from outside the building.

Westman, aged 23, died in the incident from a self-inflicted gunshot wound. Before taking on the name Robin Westman through a legal change in 2019, they were known as Robert Paul Westman, and had previously attended the church and its associated school located nearby.

Kory Krause, the owner of Frontiersman Sports in St. Louis Park, Minnesota, shared security footage showing Westman entering his store and legally purchasing a small pre-owned .38 Special revolver four days before the shooting. Krause mentioned that this gun was not used in the incident at Annunciation Catholic Church.

Westman can be seen holding a firearm at Frontiersman Sports. (Kory Krause)

“There were no signs of concerning behavior from the individual. They acted entirely normal,” Krause stated. “They blended in with other customers, communicated appropriately, appeared genuine, friendly, personable, and, if we may say, ‘normal.’ Everyone at Frontiersman is deeply saddened by this tragedy. We constantly question if we overlooked something or if there was anything more we could have done, but regrettably, the answer is no.”

Upon entering Westman’s details into the FBI’s National Instant Criminal Background Check System, a “proceed” signal was prompted, and the firearm purchase proceeded legally, Krause explained.

Robin Westman was seen browsing Frontiersman Sports. (Kory Krause)

“My staff has a stellar reputation with local and federal law enforcement for being the best in the business at weeding out bad actors. All my staff has many years’ experience in detecting and preventing attempted straw purchases, sales to those who appear mentally unstable in any way, suicidal, homicidal, intoxicated or under the influence of drugs, and those we deem incompetent, unsafe or unfit to possess a firearm for various other reasons,” Krause said. 

“We decided to come forward with the information we have regarding the shooter in the hope that it would add some more perspective to the horrible situation that occurred,” he added.

Fox News Digital reached out to the Minneapolis Police Department for comment.