Defense Criticizes Investigation for Lack of Additional Suspects in Double Homicide Trial
Prosecutors say evidence has linked Derrick James Jackson to the crimes, but defense said not enough testing was conducted in the investigation to rule out other suspects
By Maggie Dresser
A Flathead County jury on April 3 heard more witness testimony in the case against 39-year-old Derrick James Jackson, who is standing trial for killing his mother along with her partner at their Bigfork residence in 2022.
Jackson has pleaded not guilty to two felony charges of deliberate homicide in the deaths of 65-year-old Stanley Grotberg and 62-year-old Tricia DeMotts. He has also been charged with a third felony charge of tampering with or fabricating evidence and a fourth felony charge of criminal possession of dangerous drugs. Flathead County District Court Judge Amy Eddy is presiding over the trial, which began March 31 with jury selection, opening statements and initial witness testimony.
On the fourth day of trial, the jury heard from Patrol Commander Luke Foster, who at the time worked as a detective with the Flathead County Sheriff’s Office and interviewed Jackson after his arrest.
During Deputy Flathead County Attorney Amy Kenison’s questioning, Foster told jurors that during the interview with Foster, Jackson denied being under the influence of any drugs and his answers were inconsistent. At first, he told law enforcement he was living with family but then said he couldn’t remember where he slept the previous night.
Jackson ended the interview when law enforcement began asking questions about his mother, Foster said.
Foster also told the jury that he was in contact with the defendant’s father, John Jackson, after learning his son was a suspect in the murder. Foster said he advised John not to visit with Jackson because jail visits are recorded, which he ignored. Video footage later revealed Jackson saying he was defending himself and he was “trying to not get killed.”
The jury also learned from law enforcement that Jackson was the only suspect in the case, which his defense team criticized.
“Based on the circumstances surrounding the timeframe, the ability, the fact that he was located with what believed most likely to be the murder weapon, the fact that he was wearing Stanley’s clothing directly after when we believed this occurred – all of this together led me to believe he likely committed the act,” Foster said.
Prior to Foster’s testimony, the jury also heard from Montana State Crime Lab officials who tested evidence in the case, which included Jackson’s jeans that he was wearing at the time of his arrest. In their reports, they found gunshot residue and blood stains on the defendant’s pants.
Dr. Travis Doria, a forensic scientist with the Montana State Crime Lab, said he found gunshot residue on Jackson’s jeans and hoodie. Joe Pasternak, a former forensic scientist at the crime lab, testified that Grotberg’s blood was found on the defendant’s clothing.
But during defense attorney Levi Roadman’s cross examination, he criticized law enforcement officials for only sending Jackson’s belongings to the state crime lab to be analyzed and not the victims’ as well.
“It’s reasonable to believe that someone else could have been the suspected shooter,” Roadman said.