Trial begins in rural Ottawa manslaughter case

The prosecution said Mason Shannon killed Ottawa man Michael Castelli by recklessly keeping him in a chokehold longer than necessary in an altercation.

The defense said no crime was committed, because Castelli was not choked to death, but rather died from his heart giving out, caused by a prior cardiac condition, exertion and a drug in his system.

Those were the rival versions of Castelli's death laid out Tuesday on the first day of Shannon's involuntary manslaughter trial.

Shannon, 43, of Iowa City, Iowa, was charged in September 2017 with causing Castelli's death July 20, 2017, at Bonnie Plants, a commercial plant grower just northeast of Ottawa, where Shannon worked and temporarily lived.

According to Shannon's attorney, Douglas DeBoer, of Joliet, Shannon was acquainted with the 32-year-old Castelli, ran into him at an Ottawa bar the night in question and invited him to Bonnie Plants, where a number of other men were present.

Castelli eventually went out of control, punched one man and choked Shannon at different points during the night. Later, Shannon and other men tried to subdue Castelli, with Shannon putting his arms around Castelli's neck.

Prosecutor Greg Sticka said the other men eventually disengaged from Castelli, but Shannon continued holding Castelli's neck and choking him to death.

"It was excessive. He maintained the chokehold too long," Sticka said.

Castelli had alcohol, marijuana and a hallucinogen in his system.

DeBoer said the combination of Castelli's bad heart, the hallucinogen and the exertion of the altercation caused Castelli to die, not by Shannon's arm around Castelli's neck.

"There was simply no crime here," DeBoer said.

A La Salle County deputy sheriff was called to the scene to help see to Castelli. When the deputy arrived, Castelli was unresponsive and Shannon helped the deputy do CPR on Castelli, DeBoer noted. Castelli was pronounced dead at OSF St. Elizabeth Medical Center in Ottawa.

Under questioning by DeBoer, the pathologist who autopsied Castelli, Dr. Valerie Arangelovich, would not budge from her position Castelli died from choking. DeBoer pointed out a doctor hired by the defense disputed Arangelovich's conclusion. Arangelovich acknowledged another competent doctor could arrive at a different finding, but nonetheless held her view was correct.

Trial ended Tuesday afternoon, with prosecutors continuing to make their case. When it comes time for the defense to present their side, DeBoer said Shannon will testify. Trial resumes Wednesday afternoon.

Shannon opted to have Chief Judge H. Chris Ryan Jr. decide guilt or innocence, rather than a jury.