A distraught Derrick James Jackson told jurors Friday that he killed Stanley Grotberg after the 65-year-old shot dead Jackson’s mother in the trio’s Bigfork home in October 2022.  

Prosecutors charged Jackson, 39, with the murders of both Grotberg and 62-year-old Tricia DeMotts after authorities found their bodies inside their Esteban Lane house during an Oct. 28, 2022 welfare check.  

Jackson, who was found that same day with the loaded .40-caliber Smith and Wesson used in the killings and a spare magazine, has pleaded not guilty to all charges, including two counts of deliberate homicide.  

His April 4 testimony came on the fifth day of his jury trial in Flathead County District Court and shortly after the prosecution rested its case. While Deputy County Attorneys Amy Kenison and Katie Handley had linked Jackson to the murder weapon, and demonstrated he had both gunshot residue and DNA likely matching Grotberg on his clothing at the time of his arrest, they stopped short of reconstructing what happened inside the Esteban Lane home on the day of the killings.  

Jackson, one of two witnesses called by defense attorneys Thomas Schoenleben and Levi Roadman, testified that the day unraveled when an angry Grotberg began screaming at DeMotts sometime after returning from Kalispell with groceries. Jackson remembered getting between them and warning Grotberg against berating his mother.  

“I said it meaner than that, but that’s what I said,” Jackson recalled.  

Grotberg grew quiet and then stalked outside of the home and over to a parked Nissan Pathfinder, where he retrieved the black semiautomatic Smith and Wesson from a blue case, Jackson said. Returning to the home, Grotberg threatened DeMotts with the gun in the kitchen, Jackson recalled. 

That prompted him to launch himself at Grotberg, he said. The two wrestled and Jackson said he came away with the gun. After hitting Grotberg with it, likely leading to the blood investigators later found in the kitchen, Jackson said he pulled the magazine out and tossed the weapon to the floor.  

Grotberg, he said, later picked up the unloaded weapon and headed for a bedroom in the home where he was joined by DeMotts. 

That’s when Jackson said he heard a gunshot. It was followed by the sound of someone gasping, he said, his reddened face contorting under questioning from Roadman. 

Investigating, he said he found his mother shot and half off the bed. Bursting into sobs, Jackson recalled pulling her onto his lap.  

“What happened next?” Roadman asked him.  

“[Grotberg] came over to the side of the bed and he pulled her off the bed,” Jackson said. “He grabbed hold of my mom and pulled her off the bed and he shot her.” 

Jackson said he tried and failed to stop Grotberg from pulling the trigger. The two began fighting over the weapon a second time and Jackson again came away with it, he said.  

“I'm just asking what he was doing, and he says, ‘[expletive] you,’ and he comes running at me and I shot him,” Jackson said.  

PROSECUTORS HOMED in on Jackson’s actions following the killings during their cross-examination, noting that he had access to both a phone in the home and at least two mobile phones. Handley asked him whether he could have called 911. 

“Yeah,” Jackson replied.  

Then she turned to the various law enforcement personnel Jackson interacted with prior to the discovery of the bodies.  

Aaron Westphal, a corporal with the Sheriff’s Office in 2022, testified earlier in the week that he confronted Jackson that evening after Esteban Lane residents reported him acting erratically in the neighborhood. After finding a magazine and a bottle of Grotberg’s prescription medication on Jackson — the gun was found discarded in nearby tall grass — Westphal said he thought he was dealing with a trespassing or petty theft case.  

Taken to the Flathead County Detention Center, Jackson fielded more questions from Westphal and met jail personnel.  

“At no point in time did you tell any of these people that your mother is dead?” Handley asked him.  

“No, I don’t think so,” he said.  

“Did you tell any of them that [Grotberg] had killed your mother?” she asked.  

“No.”  

“Did you tell any of them that you had killed [Grotberg]?”  

“No,” Jackson replied.   

Jackson later said that he assumed Westphal had picked him up in connection with the killings. He also testified, when asked why he left the home with the loaded gun, that his memory of the aftermath of the shootings was hazy. 

That prompted Handley to play again portions of the recording taken from Westphal’s body camera. Westphal, she noted, had asked about Grotberg’s whereabouts. He asked if Grotberg was OK, Handley reminded Jackson.  

“And you said, ‘He should be,’” she said. Jackson agreed. 

But Jackson knew that Grotberg was dead, Handley pointed out. 

"Yeah,” Jackson acknowledged. 

JACKSON’S ATTORNEYS rested their case following his testimony early Friday afternoon. The only other witness called by Schoenleben and Roadman was Jackson’s father, John Jackson. 

He testified that Jackson had been in a car wreck earlier in 2022 that left him injured and bedridden. Even after regaining the strength to walk again, he needed help to do so, John Jackson said.  

He also testified that DeMotts had previously accused Grotberg of abuse. John Jackson said she had shown him bruising she alleged came from Grotberg.  

But under cross-examination from Kenison, John Jackson said Grotberg wasn’t the only person DeMotts had accused of abuse. She reminded him of a conversation they had had about the abuse allegations in her office prior to the trial.  

“And what did you tell me?” Kenison asked him. 

“I would take it with a grain of salt ...,” John Jackson said. “When we were together, she would say stuff that I did that I knew wasn’t true.” 

Judge Amy Eddy, who is presiding over the trial, scheduled closing arguments for Monday morning. Jury deliberations are expected to follow. 

News Editor Derrick Perkins can be reached at 758-4430 or [email protected].