On Friday, March 17, 2023, at 4:03pm, law enforcement responded to 618 West Boone Street after receiving a 911 call reporting someone had been injured at this location and was not breathing. Upon arrival, officers found a 27-year-old male deceased. The victim was identified as Isaiah Montell Forest, age 28, of Marshalltown. On March 18, 2023, an autopsy of the victim was performed by the Iowa Office of the State Medical Examiner. The autopsy revealed the victim died as the result of a gunshot wound.
On Sunday, March 19, 2023, law enforcement arrested Amarrion Demeir Isom, age 20. Mr. Isom was charged with Murder in the First Degree (Class A Felony).

A trial was held in Marshall County District Court beginning on February 13, 2024. On February 19, 2024, a Marshall County jury convicted Mr. Isom on the charge of Murder in the First Degree. Chief Michael Tupper stated, “Our thoughts remain with the family and friends of Isaiah Forest. This was a senseless crime. We are pleased with the jury verdict and we thank the jurors for their time and work. I am also thankful for the hard work of the law enforcement officers, detectives, prosecutors, and crime scene investigators involved in this case. These dedicated professionals work tirelessly to ensure violent criminals are brought to justice.”
The Iowa Division of Criminal Investigation, the Marshall County Attorney’s Office, and the Iowa Attorney General’s Office assisted with this investigation.
For more information, please contact Police Chief Michael Tupper by calling 641.754.5771 or via email at mtupper@marshalltown-ia.gov.