Robert R. Ernst of Perkins Oklahoma passed away peacefully in his home with family by his side on February 4, 2023 at the age of 80. Robert was born on December 11, 1942 to Robert B. and Constance F. Ernst in Stillwater Minnesota and moved to Cambridge Minnesota at an early age. During his high school years his love for law enforcement began. He married the love of his life Sandra I. Sweitzer on June 26, 1965 in St. Paul, Minnesota. He began his law enforcement career with the Saginaw County Sheriff's Office and later at the Buena Vista Police Department in Michigan and moved up the ranks and ended his law enforcement career as a Detective Sergeant. He and Sandra later moved back to Minnesota and created JB Enterprises which promoted and held Country & Western shows during the 1970s and 1980s. He has numerous pictures with some of the great singers from Conway Twitty, Leroy Van Dyke, Barbara Mandrell, Farron Young, Ed Bruce and Sylvia just to name a few. He missed law enforcement, so he started his passion for historical research involving law enforcement and the Old West. His research brought him on travels all over the United States. He later moved his family to Stillwater Oklahoma to be closer to his research. He has authored and published over fifty journal articles in such publications as Oklahombres, NOLA, WOLA, Frontier Times and WWHA. He authored and published two books: Killin' Cops and Robbin' Banks The Life and Crimes of Lawrence DeVol and Deadly Affrays The Violent Deaths of U.S. Marshals which told the story of 288 U.S Marshals killed in the line of duty. He spent over 20 years documenting the line of duty deaths of the U.S Marshals. He was working on a second installment to Deadly Affrays at the time of his death. His passion of history also involved old planes of the military and he enjoyed going to air shows to see planes such as B-17 and B-52 bombers and was a member of the Commemorative Air Force. He is preceded in death by his parents, Robert B. and Constance; his in-laws Donald L. and Mary E Sweitzer; his wife of over 45 years Sandra I. Ernst; grandson Rhett L. Ernst and great-grandson Dexton Wayn Rice. He is survived by his son Robert D. Ernst and wife Tracey of Perkins Oklahoma and daughter Michelle L. Phelps and husband Dane of Stillwater Oklahoma. He is survived by his grandchildren: Augusta G. Sweitzer, R. Tanner Ernst, Macy L. Ernst, Emmaline R. Dethloff, Chloe E. Phelps, Dakota R. Phelps and 6 great-grandchildren. As well as numerous other family members and friends. The family would like to thank his caregivers Robin and Jennifer Thomas for all the support they provided. Memorial contributions may be made in his name to the Commemorative Air Force via www.commemorativeairforce.org . Memorial services are pending at this time. Condolences may be emailed to the family and an online obituary may be viewed by visiting www.strodefh.com .