Chad Isaak convicted of killing 4 in Mandan

After about a little more than four hours of deliberation, the jury found Chad Trolon Isaak guilty of slaying four people in Mandan on April 1, 2019.

Chad Isaak, right, watches with defense attorney Jesse Walstad on Friday, Aug. 20, 2021, as jurors leave the courtroom after convicting Isaak on four counts of murder and other charges in the April 1, 2019, slayings of four workers at RJR Maintenance and Management in Mandan. Tom Stromme / The Bismarck Tribune
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MANDAN, N.D. — After nearly three weeks of court proceedings that contained detailed testimony, jurors found Chad Trolon Isaak guilty on four charges of murder on Friday, Aug. 20, for the deaths of four employees of RJR Maintenance & Management in Mandan more than two years ago.

Jurors returned the guilty verdict after about 4 hours and 15 minutes of deliberation over two days. Isaak faces the possibility of life in prison now that he has been convicted of shooting and stabbing Robert Fakler, Adam Fuehrer, William Cobb and Lois Cobb on April 1, 2019.

The verdict was the final step of Isaak’s three-week trial that was delayed four times. Jurors heard testimony from almost 70 witnesses and were presented with hundreds of pieces of evidence, including weapons, clothing and video surveillance footage.


Judge David Reich read the guilty verdict, and family members in the court room audibly sighed and began crying and hugging one another.

Reich ordered a pre-sentencing investigation to learn more about Isaak himself and determine whether there are any extenuating circumstances that should influence his sentence.

Morton County prosecutor Gabrielle Goter, center, speaks with reporters following the conviction of Chad Isaak on Friday in the April 1, 2019, quadruple homicides at RJR Maintenance and Management in Mandan. Others are, from left, lead investigator Joe Arenz, with prosecutors Austin Gunderson and Karlei Neufeld. Tom Stromme / The Bismarck Tribune

"It hasn't been an easy road," said prosecutor Gabrielle Goter, adding that the prosecution and victim's family members feel relieved about the verdict. "Today, the verdict has validated the thoroughness of the investigation and the whole process that we've tried to go through from start to finish."

Defense attorney Jesse Walstad said he plans to meet with Isaak next week to discuss next steps, including possibly appealing the verdict.

"Obviously, this is not the result that we had hoped," Walstad said. "We've done our best to zealously advocate for our client."

Walstad said he believes jurors considered the evidence they were given to the best of their ability, and he trusts the jurors "upheld their charge."


Jurors ultimately sided with the prosecution's case that Isaak, 47, drove to Mandan on the morning of April 1, 2019, and parked a white pickup at a McDonald’s about a mile away from RJR Maintenance. Prosecutors alleged that Isaak then walked to RJR Maintenance and arrived at around 6:42 a.m., when William and Lois Cobb were already inside the building. Fuehrer and Fakler arrived shortly after.

During the trial, the prosecution showed the jury several presentations with video and photographic evidence from the scene. They argued that within the 21-minute timeframe the suspect was inside RJR Maintenance, the person stabbed all four victims around 100 times collectively and shot William Cobb, Lois Cobb and Fuehrer at least eight times altogether.

After the slayings, the suspect, wearing an orange face mask and jacket, and dark pants, shoes and gloves, stole an RJR Maintenance truck and drove it a few blocks away from the building. Authorities were then able to track the suspect, who was then wearing a black coat and a camouflage face mask, getting back into the white pickup, using multiple security cameras.

Surveillance footage from numerous businesses showed the truck driving through Mandan, then to Center, North Dakota, and about 40 miles north to Washburn.

The defense argued there are many gaps between the security camera footage of the white truck from business to business, and in these gaps multiple white trucks could be seen. The limited scope of the cameras could have led authorities to track the wrong white truck, they said.

In the days following the homicides, authorities sent out notifications to other law enforcement agencies statewide alerting them of the suspect’s vehicle. A detective from the McLean County Sheriff’s Office recognized the truck as his chiropractor’s — Isaak — because of some distinct rust stains above one of the rear tires.

Law enforcement then detained Isaak on April 4, 2019, and executed search warrants on his Washburn mobile home, chiropractic clinic and pickup.

Within Isaak’s residence, investigators found a reversible orange and camouflage face mask, an orange zip-up jacket, black shoes, black pants and two black jackets inside of the dryer. Authorities also uncovered a knife from the washing machine, which was sitting under some wet rags and clothing.


Law enforcement believed the clothing discovered in the dryer was the same as the suspect's.

However, defense attorney Bruce Quick during his closing argument said none of the victim's DNA was found on the clothing, and Isaak's DNA was not found at the crime scene. Investigators said they believe the clothes were bleached, therefore destroying any DNA, but Quick said the investigators who wrote reports about searching Isaak's clothing did not mention the smell of bleach on the clothes.

Earlier this week, a former North Dakota Crime Laboratory forensic biologist testified that the blood of Fakler and Lois Cobb could not be excluded as the sources for at least one of the blood spots found in Isaak’s vehicle. An ATF agent also testified regarding fiber analysis, saying fibers from an orange and camouflage face mask and an orange jacket were “indistinguishable.”

The prosecution during its closing arguments earlier this week urged jurors to believe the science and said the prosecution's theory that evidence found in Isaak's truck and residence being simply a coincidence was "beyond ridiculous."

Readers can reach Forum reporter Michelle Griffith, a Report for America corps member, at

Michelle (she/her, English speaker) is a Bismarck-based journalist for The Forum of Fargo-Moorhead and Report for America, a national service organization that places journalists in local newsrooms to report on under-covered topics and communities.
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