The sentence closed a case that stretched from a Zeeland Township home to Las Vegas after a New Year’s Day argument over where the couple would live.

GRAND HAVEN, Mich. — A Michigan man was sentenced March 30 to 32 1/2 to 90 years in prison for killing his longtime girlfriend during a New Year’s Day argument over living arrangements, then fleeing west with cash before later confessing in Las Vegas, authorities and court records said.

Randall Alan Grinwis, 59, had already been convicted of second-degree murder and larceny in the death of 63-year-old Donna Hyma, his partner of nearly two decades. The sentence in Ottawa County Circuit Court brought formal punishment to a case prosecutors said was not a brief loss of control but a sustained attack inside the couple’s Zeeland Township home. The ruling also followed emotional statements from Hyma’s relatives, who told the judge they had trusted Grinwis and now measure time by the day she died.

The killing happened Jan. 1, 2024, at the couple’s home on Patti Place in the Ottogan Mobile Home Estates in Zeeland Township. Prosecutors said Grinwis and Hyma had been drinking and arguing about their living arrangements when he placed his forearm across her neck and pushed down while she sat on a couch. He later told detectives that he “snapped,” a phrase jurors heard more than once during trial through recorded confessions. Deputies were sent to the home that night for a welfare check, and Hyma was found unresponsive. An autopsy later determined she died of asphyxiation, turning what first appeared to be a possible natural death into a homicide case. By the time investigators began sorting out what happened, Grinwis was already gone.

According to testimony and court reporting from the trial, Grinwis withdrew $1,800 that belonged to Hyma’s brother and had been meant for a lockbox in the home. Prosecutors said he took the money after Hyma’s death, packed a bag and drove away. At least 90 minutes later, while on Interstate 196 in Van Buren County, he called 911 to ask for a welfare check, then threw his cellphone from the vehicle because he feared he could be tracked. Senior Assistant Prosecutor Ben Medema said Grinwis stopped at a casino in Michigan City, Indiana, drove to Chicago and flew from O’Hare International Airport to Las Vegas. There, prosecutors said, he stayed in a hotel, gambled and kept moving until the money was gone. Grinwis later told police he would have kept running if he had been able to do so.

The evidence at trial centered heavily on Grinwis’ own words and the reconstruction of the final hours in the home. Detectives told jurors that Grinwis confessed first to a Las Vegas police detective after walking into a department kiosk on Jan. 15, 2024. He then repeated the account to Ottawa County investigators weeks later when they traveled west to arrest him. Detective David Bytwerk testified that he had Grinwis physically demonstrate the position he used during the attack. Jurors also heard that Grinwis said Hyma did not fight back and that he checked for a pulse afterward but could not find one. Defense arguments sought to frame the killing as a sudden act during a drunken argument, but prosecutors leaned on the duration of the compression and the sequence that followed to argue that the case supported murder, not a lesser offense.

Judge Karen Miedema made clear at sentencing that she viewed the killing as preventable. “This was an incident that could have been totally avoidable,” the judge said, adding that Grinwis had options and chose “a very drastic and very evil option.” Prosecutors struck a similar note. One told the court that the killing should not be softened by the defendant’s repeated claim that he snapped. “This was not a snap,” the prosecutor said, arguing that Grinwis had about 40 seconds to stop and did not. Earlier in the case, the jury had been given options that included second-degree murder and voluntary manslaughter after the parties agreed prosecutors would no longer pursue a first-degree murder outcome. The jury returned guilty verdicts in less than two hours after a three-day trial.

Hyma’s family used the sentencing hearing to shift the courtroom’s focus away from the defendant and back to the woman they lost. Her daughter, Lisa Vanderyacht, said the family’s grief was sharpened by the fact that Grinwis had long been part of their lives. “I trusted him with her life, and now I have to live with that for the rest of mine,” Vanderyacht told the court. She said she lost not just her mother, but also the person she thought Grinwis had been for 20 years. Relatives described Hyma as funny, social and deeply loved. Those memories stood in sharp contrast to the case record: a couch in a small home, a late-night welfare check, a drive out of state and a confession delivered far from Ottawa County.

Grinwis’s case now stands at its sentencing endpoint. He will serve the prison term imposed March 30 unless a higher court later changes the outcome on appeal, and Hyma’s death remains recorded in court as a homicide that began with an argument and ended with a sentence likely to keep the defendant incarcerated for the rest of his life.

Author note: Last updated April 19, 2026.