A "dispute between brothers" led to 59-year-old Robert Bracken allegedly killing his own son, brother, and another man before turning the gun on himself in a North Dakota wheat field on Aug. 29, Towner County Sheriff Andrew Hillier said Friday. 

Robert Bracken was working the harvest in the northeastern part of the state with his brother, 64-year-old Richard Bracken, and his son, 34-year-old Justin Bracken. The field was owned by 56-year-old Douglas Dulmage, who was also killed. 

The dispute that led up to the shooting had been "escalating for a week or more," the sheriff said. 

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Evidence at the scene indicated that Robert Bracken shot and killed the three men with a .357 caliber revolver before taking his own life. He was in possession of the gun and had a fatal self-inflicted gunshot wound, according to the sheriff. 

North Dakota murder victim

This October 2020 photo provided by Pat Traynor shows Douglas Dulmage, who was shot and killed on his farm on Aug. 29 near Cando, North Dakota.  (Pat Traynor via AP, File)

Dulmage was a member of the North Dakota Farm Bureau and served as president for the Benson County Farm Bureau

"It is hard to understand why something like this would happen in a rural farming community," North Dakota Farm Bureau President Daryl Lies said in a statement. 

"When evil presents itself, it can be devastating but we must remember there is more good than evil in our world. Doug’s dedication to agriculture and love for his family will forever be remembered."

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The Brackens were from Leeds, which is about 20 miles southwest of the scene of the triple murder-suicide in Cando.