Katherine Ann Frank was a beloved sister, daughter, granddaughter, and friend who had found her calling in law enforcement. At 26 years old, the female deputy was known for being incredibly funny, with a personality that allowed her to get along with just about everyone. A 2018 graduate of Dawson-Boyd High School in western Minnesota, she had successfully completed the Law Enforcement Academy only two years before her death.
Her siblings remembered a lifetime of memories and a bond that nothing could break, recalling chaotic and laughter-filled morning drives to school. Katherine, her brother Thomas said, had a special way of making ordinary moments memorable. Outside of her work with the Minnehaha County Sheriff's Office, she enjoyed reading, cooking, playing video games, and spending time with her boyfriend, Austin, and her two beloved dogs, Ares and Aspen.
On the evening of Friday, October 9, 2026, Deputy Frank and two other officers responded to a residence in Sioux Falls, South Dakota. They were there to serve a mental health hold on 39-year-old Brandon John Oetken. According to court documents, a witness stated that Oetken recognized the responders as police officers. As they spoke with him in the entryway of the home, Oetken retreated inside. The officers followed to maintain contact, standing close together in the entryway. It was then that Oetken allegedly produced a handgun, pointed it at the officers, and fired as they tried to retreat. Deputy Frank was struck at close range. Another officer returned fire, hitting Oetken multiple times.
Deputy Frank was rushed to a local hospital in critical condition. She fought for three days, surrounded by her family and loved ones, before she passed away from her injuries on Monday, October 12, 2026. Her death marked a rare and profound loss for the city, which had not seen an officer die by gunfire in a very long time. The man accused of shooting her, Brandon John Oetken, was initially charged on October 10 with three counts of attempted first-degree murder and three counts of aggravated assault on a law enforcement officer. Authorities indicated the charges could be amended following Deputy Frank's death.
The loss of Deputy Frank sent waves of grief far beyond Sioux Falls. In the days that followed, a memorial outside the Sioux Falls Law Enforcement Center grew with flowers, balloons, candles, and handwritten notes as community members came to pay their respects. A GoFundMe campaign established by the Minnehaha County Sheriff’s Office for her family quickly surpassed its fundraising goals, raising more than $100,000. Law enforcement officers from across the country traveled to Sioux Falls to honor her and show support for her family and the department she served.
On the day of her funeral, thousands gathered at the Denny Sanford Premier Center for a day of sorrow and remembrance. Hundreds of law enforcement vehicles formed a procession that stretched for miles, traveling from the George Boom Funeral Home, through the heart of the city, to the service. Citizens of all ages lined the streets, stopping their daily activities to pay their respects. "Seeing so many people, just everybody coming here from work, school, kids at the playground lining the fence lines, it takes your breath away,” said Minnehaha County Captain Joe Bosman.
During the service, officiants and colleagues spoke of the profound loss. "This one hurts. It hurts our entire agency," said Minnehaha County Captain Josh Phillips. "We’ve never experienced a loss like this." Katherine’s siblings shared personal stories, expressing their deep love and grief. "We both chose to go into law enforcement. We knew the risks. But I never imagined I’d have to stand here and say goodbye to my little sister. My best friend," said her sister, Kristyne Hamberg-Frank. The ceremony concluded with the placement of white carnations on her casket, a three-volley salute, and the playing of Taps before a final procession carried her to her resting place. The case against Brandon John Oetken was proceeding through the court system as of October 2026.
