CEDAR RAPIDS — A Northern Iowa felon who was already on federal supervised release has been sentenced to more than five years in prison after authorities say he holed up in his home with a gun, triggered an hours-long standoff and accidentally fired a shot that struck the foundation of a nearby home.
Robert Dettbarn (pictured at top in jail), 34, of Independence, was sentenced after pleading guilty on January 21, 2026, to being a felon in possession of a firearm.
Federal prosecutors said the case marked Dettbarn’s second conviction for being a felon in possession of a gun.
The case traces back to September 8, 2025, when members of the United States Marshals Service Northern Iowa Fugitive Task Force went to Dettbarn’s home in Independence. Officers were attempting to arrest him on a federal warrant tied to alleged violations of supervised release.
Dettbarn had previously been convicted in federal court in 2018 of being a felon in possession of a firearm.
When officers arrived at his home and determined he was inside, they attempted to persuade him to come out. Prosecutors said Dettbarn refused.
Officers could see Dettbarn inside the home with a gun, according to information presented at sentencing.
The standoff lasted about five hours before an Iowa State Patrol tactical unit arrived to assist. Officers deployed tear gas into the home.
Authorities then heard a gunshot. Prosecutors said Dettbarn accidentally fired his gun, striking the foundation of a nearby home.
Dettbarn then left the home and was taken into custody.
Chief U.S. District Court Judge C.J. Williams sentenced Dettbarn in Cedar Rapids. Between the new firearm sentence and a sentence for violating supervised release, Dettbarn received a total prison term of 61 months.
He must also serve three years of supervised release after his prison term.
There is no parole in the federal prison system.
Federal law generally prohibits convicted felons from possessing firearms or ammunition. For offenders already on supervised release, a new gun offense can bring both a new federal sentence and additional prison time for violating the conditions of release.
The case was prosecuted by Assistant United States Attorney Anthony Morfitt and investigated by the United States Marshals Service.
Federal officials said the case is part of Operation Take Back America, a nationwide Department of Justice initiative targeting violent crime, cartels, transnational criminal organizations and illegal immigration-related enforcement priorities.
Dettbarn remains in the custody of the United States Marshal until he can be transported to a federal prison.