MARSHALLTOWN — After almost four hours of deliberation following a weeklong trial, a Marshall County jury found Amarrion Demeir Isom guilty of first-degree murder for his role in the 2023 shooting death of Isaiah Forest on Monday afternoon.

The jury deliberated a few hours on Friday before being excused for the weekend, and another hour after reconvening Monday afternoon. Roughly 25 people sat in the chairs and benches in the fourth-floor courtroom and waited to hear what the jury determined.

Isom, 21, a former Fort Dodge resident, did not show much emotion as the verdict was read, nor as he was escorted out of the courtroom by Marshall County deputies. One of his supporters told Isom they were going to fight the verdict as he waved goodbye.

District Court Judge Amy Moore asked Marshall County Attorney Jordan Gaffney and defense attorney Aaron Siebrecht if they wanted a poll of the jurors. Gaffney said he did not, but Siebrecht asked for the poll. One-by-one, all of the jurors affirmed they found Isom guilty of first-degree murder.

Gaffney asked for Isom to be held without bond, which Moore approved.

Isom was accused of murdering 27-year-old Isaiah Forest on March 17, 2023, at a Marshalltown residence. He pleaded not guilty on March 29, 2023, and the trial began Feb. 12.

Assistant Attorney General Monty Platz helped the prosecution during the trial, but was absent on Monday. During his closing statements Friday, he told the jury Isom killed Forest for a perceived lack of respect, in addition to a drug debt.

The prosecution said Isom took a shotgun to the West Boone Street residence where Forest was staying, pulled the trigger at close range and then took steps to cover it up. Prosecutors said Isom tried to get rid of the evidence, established an alibi and told conflicting stories to two separate law enforcement officers.

Attorney Ted Fisher gave the closing statements for the defense and asked the jury to find Isom guilty of involuntary manslaughter. According to Iowa Code, involuntary manslaughter occurs when “the person unintentionally causes the death of another person by the commission of a public offense other than a forcible felony or escape.”

He said there were inconsistencies in the testimony of a witness, and that the tragedy of Forest’s death was the result of something going wrong.

In a press release issued Monday afternoon, Marshalltown Police Chief Mike Tupper indicated that he was happy with the outcome and praised the professionals who played a role in securing a guilty verdict.

“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,” Tupper said. “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.”

Gaffney expressed a similar sentiment.

“From initial response to verdict, this case represents a tremendous effort and work of collaboration by everyone involved. It’s an honor to have been part of this journey. I would like to extend my gratitude to the Marshalltown Police Department, the Iowa Division of Criminal Investigation, the Office of the Attorney General, and our wonderful team at the Marshall County Attorney’s Office,” he said.