On April 1, 2019, four people were found dead at RJR Maintenance & Management in Mandan, North Dakota. The victims were Adam Fuehrer, 42, an employee of five years who loved working on cars, cooking, and spending time with his family and who left behind a wife and two sons; co-owner Robert Fakler, 52; and married couple Bill Cobb, 50, and Lois Cobb, 45. All four had been shot and stabbed.

The Mandan Police Department arrested 44-year-old chiropractor Chad Isaak, who lived in a mobile home park managed by RJR, three days after the bodies were discovered. Isaak was charged with four counts of murder and was being held on $1 million bail as he awaited trial. Investigators had not publicly identified a clear motive for the killings.