The attorney for a man accused of killing his ex-wife, a DeKalb County prosecutor, by shooting her 15 times in front of their 5-year-old daughter a year ago is arguing his client's actions may have been the result of neurological damage sustained from a workplace incident.

Madison-based lawyer Douglas Phebus entered a not guilty by insanity plea for Ulisses Medina Espinosa, 32, who was set to head to trial mid-February but will instead undergo a trial in Dodge County, Wisconsin Circuit Court the first week of June. Medina Espinosa is facing first-degree intentional homicide charges in connection to the brutal slaying of DeKalb County assistant state's attorney Stacia F. Hollinshead, 30, on March 23, 2019. Hollinshead was an Army veteran and a Northern Illinois University law school graduate who'd been hired by the State's Attorney's Office five months before her death.

Phebus did not respond to requests for comment Friday.

If convicted, Medina Espinosa could face life in prison. He's being held at Dodge County Jail in Juneau, Wisconsin, after a judge set his bond at $2 million days after the incident.

According to Dodge County Court records, the former DeKalb resident was scheduled to head to trial in a few weeks, but his case changed lawyer hands on January 10. His new lawyers instead asked Dodge County Circuit Court Judge Steven Bauer to postpone the trial, and entered a not guilty by insanity plea on Wednesday, changing Medina Espinosa's initial not guilty plea which he entered on May 30, 2019, records show.

The Beaver Dam Daily Citizen reported Phebus said he is reviewing whether Medina Espinosa was exposed to some chemicals 10 days before the shooting while working at Kraft Heinz in Beaver Dam that may have caused neurological symptoms which led to him becoming violent.

Medina Espinosa had a history of domestic abuse against Hollinshead, DeKalb County court records show, though they had been divorced since 2016 and Hollinshead had full custody of their daughter and an order of protection granted to her against her ex-husband. On the day of the shooting, Hollinshead drove their daughter to Beaver Dam to visit with Medina Espinosa's parents, since she "felt a that she had a moral obligation" to allow her daughter to have a relationship with her grandparents, records show.

When Hollinshead and their daughter were inside his parents' home, witnesses said he arrived with gifts for the girl, and then shot her mother 15 times in the head and back, according to records.

His new trial date is set for June 1 through 5, records show.