South Dakota shooting: AG clears deputy in death of Katherine Frank
A state review found the force used in the Oct. 9 incident was warranted, as the suspect fired a revolver at the officers.
By Talia Bennett ·
State Attorney General Marty Jackley announced on Friday that a deputy with the Minnehaha County Sheriff’s Office acted within the scope of their authority during a fatal exchange in Sioux Falls. The review, conducted by the Division of Criminal Investigation, cleared the officer of wrongdoing in the shooting that killed Deputy Katherine Frank on Oct. 9.
The investigation determined the scene presented a direct threat to the safety of the responding team. Jackley stated that the use of force was justified because the situation was dangerous. "Force was warranted under the circumstances, as the situation was dangerous and posed a threat to the deputies’ safety," Jackley said. The office also noted its continued support for Deputy Frank’s family.
The incident began when three deputies arrived at a home in Sioux Falls to serve a mental health detention warrant on Brandon Oetken, 39. According to the findings, Oetken ignored multiple verbal commands to exit the residence. He then aimed a firearm at the officers and discharged it once. The bullet struck Deputy Frank. A second deputy responded by firing four shots, which hit Oetken.
Deputy Frank died on Oct. 12, 2026. Oetken sustained a gunshot wound that was not life-threatening. The other two deputies involved in the encounter were not injured. Investigators recovered a .22-caliber long-rifle rimfire revolver from the scene. Blood and urine tests for all three deputies came back negative for alcohol and illegal drugs.
The review process included a forensic examination of the crime scene, interviews with those present, and a review of body camera footage. The Minnehaha County State’s Attorney’s Office has charged Oetken with first-degree murder, second-degree murder, and additional counts. He is presumed innocent under the U.S. Constitution until proven otherwise.
Oetken’s criminal record includes a prior arrest for DUI and careless driving. In Minnesota, he was previously contacted by law enforcement after making suicidal statements while waving a gun at his mother. The South Dakota Forensic Lab and the Sioux Falls Police Department assisted in the investigation. Six officer-involved shootings have been recorded in South Dakota this year.
