Several individuals have been sentenced in the District of Wyoming for offenses related to firearms, drug trafficking, and immigration violations, according to recent announcements from the U.S. Attorney’s Office.
Milton Robert Petersen, 55, from Pavillion, received a sentence of 70 months in prison and three years of supervised release after being found guilty of being a felon in possession of firearms. On March 13, 2025, law enforcement executed a search warrant at Petersen’s residence and found him with two rifles in a camper trailer. Petersen admitted there were numerous firearms on the property. Authorities seized about 57 firearms during the search. The investigation was conducted by the Wyoming Division of Criminal Investigation and the FBI Rocky Mountain Safe Trails Task Force. Assistant U.S. Attorney Timothy W. Gist prosecuted the case. U.S. District Court Judge Alan B. Johnson imposed the sentence on January 21 in Cheyenne.
Robert Dean Campbell, 50, of Cheyenne, was sentenced to 18 months in prison and two years of supervised release for being a felon in possession of a firearm. In August 2024, Campbell was arrested by the U.S. Marshals Service at his girlfriend’s camper where officers located a Ruger 9mm pistol that he possessed illegally. The Cheyenne Police Department assisted with the investigation. Assistant U.S. Attorney Paige Hammer prosecuted this case, and Chief U.S. District Judge Kelly H. Rankin imposed the sentence on January 30.
Jason Arnold Rohrich, 49, from Rapid City, South Dakota, received two concurrent sentences: one for being a felon in possession of a firearm (135 months’ imprisonment with three years’ supervised release), and another for possession with intent to distribute methamphetamine (180 months’ imprisonment with ten years’ supervised release). Rohrich was stopped twice by law enforcement—in Wyoming and Idaho—where authorities discovered methamphetamine hidden inside vehicles along with firearms despite his status as a convicted felon prohibiting such possession. Both cases were prosecuted by Assistant U.S. Attorney Christyne M. Martens; sentencing was imposed by U.S. District Court Judge Alan B. Johnson on January 23.
Tyler L. Riser, 32, of Riverton, was sentenced for multiple offenses including distribution and conspiracy to distribute methamphetamine as well as possessing firearms in furtherance of drug trafficking crimes—receiving sentences totaling over eight years plus five years’ supervised release per count to run concurrently. The investigation followed reports of drug trafficking on the Wind River Indian Reservation and led to seizures including seven firearms and approximately 21 grams of methamphetamine.
Juan Pedro Rangel-Ventura, age 25 from Jalisco, Mexico, was sentenced to time served plus ten days to allow for deportation proceedings after pleading guilty to illegal re-entry following previous deportation in November 2022.
The United States Attorney’s Office represents the federal government in litigation within Wyoming—including criminal prosecutions for federal law violations—and manages programs aimed at improving community safety such as Project Safe Childhood (which targets technology-facilitated sexual exploitation crimes against children) and Operation Take Back America (focused on combating illegal immigration and organized crime). The office also has a Victim Witness Program dedicated to supporting victims and their families through federal criminal proceedings.
