In the quiet community of Bigfork, Montana, the autumn of 2022 was shattered by a grim discovery that would unravel a story of domestic turmoil and violence. On October 28, 2022, 65-year-old Stanley Allen Grotberg, a Caucasian male, was found deceased in his home. His death, alongside that of 62-year-old Tricia Lynn Demotts, was the result of gunshot wounds, and authorities quickly ruled it a double homicide.
The investigation into the deaths led authorities to a suspect, Derrick James Jackson, who was apprehended later that same day. Flathead County Sheriff's deputies were initially responding to reports of a man breaking into homes and vehicles in the area when they encountered Jackson. He was found wearing Grotberg's hat and jacket and was in possession of the older man's prescription medication and a firearm magazine.
After his arrest for trespassing, deputies performed a welfare check at the residence Jackson shared with his mother, Tricia DeMotts, and her boyfriend, Stanley Grotberg, where they discovered the bodies.
Derrick James Jackson was subsequently charged with two counts of deliberate homicide. During the trial, prosecutors presented evidence that pointed to Jackson as the sole perpetrator. Blood found on Jackson's jeans and sweatshirt matched Grotberg's DNA, and his clothing also tested positive for gunshot residue. The only fingerprints found on the gun case in Grotberg's vehicle belonged to Jackson.
Jackson's defense attorneys argued that he acted in self-defense. Jackson testified that Grotberg had been verbally abusive towards his mother, leading to a physical altercation. He claimed that Grotberg retrieved a pistol from his vehicle and that in the ensuing struggle, Grotberg fatally shot Demotts. Jackson stated that he then shot Grotberg in fear for his own life. The prosecution, however, highlighted inconsistencies in Jackson's statements to law enforcement and pointed to his behavior after the killings, which included not calling for help and discarding the weapon, as evidence against his self-defense claim.
In April 2025, a Flathead County jury reached a split verdict. They acquitted Derrick James Jackson of the deliberate homicide of his mother, Tricia DeMotts, but found him guilty of the deliberate homicide of Stanley Grotberg. The jury also convicted him of tampering with evidence. In June 2025, Jackson was sentenced to 100 years in the Montana State Prison for the murder of Stanley Grotberg.
