McHenry County man charged with murder of Marengo woman whose body was found in U-Haul storage unit

A former Marengo man is accused of killing his 33-year-old girlfriend in November, but it was another four months until officers discovered the woman’s body in a car inside a locked Roscoe storage unit.

A warrant has been issued for 33-year-old Jonathan Van Duyn in connection with the death of his girlfriend Michelle Arnold-Boesiger, also formerly of Marengo. The pair are thought to have been living together in the central Wisconsin town Mosinee shortly before Arnold-Boesiger went missing.

After the alleged murder, Van Duyn used Arnold-Boesiger’s phone to ask the woman’s friends and family for money, Winnebago County prosecutors said Tuesday during a news conference announcing. Van Duyn additionally tried to fill Arnold-Boesiger’s prescriptions and pawn her personal belongings, prosecutors said.

“Over the course of the next several weeks, Michelle Arnold-Boesiger’s debit card was used on multiple occasions by Jonathan Van Duyn,” Winnebago County State’s Attorney J. Hanley said in a news release. “Michelle Arnold-Boesiger’s cellular phone was still on and active at this time but always traveling directly with Jonathan Van Duyn’s cellphone.”

Van Duyn, who also goes by “Kyle,” is charged in a two-count criminal complaint with first-degree murder and concealment of a homicidal death. He is wanted on a $5 million-bond arrest warrant and could face between 20 and 60 years in prison if convicted of first-degree murder, Hanley said at a news conference Tuesday morning.

“There is no more serious crime than a murder,” Hanley said.

Van Duyn is accused of killing Arnold-Boesiger on Nov. 15, 2020, and hiding her body inside a storage facility. Months passed and the woman’s body was partially mummified by the time police searched the Roscoe U-Haul unit in early March, Winnebago County court records show.

Those who knew the woman have described her as a loving mother and “family-oriented” person with a “big heart.”

Chris Szymanski, a former boyfriend of Arnold-Boesiger’s, said she was “a sweetheart” who loved dogs and saw the best in people.

“She was just so kind,” Szymanski said. “She didn’t deserve this at all.”

It’s unclear exactly how Arnold-Boesiger died, but the medical examiner who performed her autopsy posited several theories.

According to court records filed Tuesday morning in Winnebago County Court, Arnold-Boesiger might have died of homicide by asphyxiation, an accidental overdose, or a combination of the two – for example, “that she was rendered unconscious by drugs and then asphyxiated,” prosecutors wrote in a probable cause statement. The medical examiner found no significant injuries on her body.

Investigators were able to confirm, however, that Van Duyn was the registered owner of the black Jeep Renegade where officers ultimately discovered Arnold-Boesiger’s body, according to the release.

“Her body had been covered in blankets and bedding. There were also odor eliminator in the vehicle,” Hanley said in the release.

Last week, the Winnebago County Coroner’s Office denied the Northwest Herald’s public records request seeking information about Arnold-Boesiger’s autopsy. The coroner’s office cited an exemption claiming that releasing that information would “create a substantial likelihood that a person will be deprived of a fair trial or an impartial hearing.”

The Northwest Herald since has submitted a request for review to the Illinois Attorney General’s Office Public Access Counselor.

The weeks before Arnold-Boesiger’s disappearance

The state’s attorney on Tuesday identified a Wisconsin construction worker named Dean Ellis as the last person to “have a physical encounter” with Arnold-Boesiger.

“Dean Ellis said that this was in the late evening hours of November 14, 2020, or the early morning hours of November 15, 2020, and she was with Jonathan Van Duyn,” prosecutors wrote in the probable cause statement.

Van Duyn and Arnold-Boesiger were in the process of buying and renovating a fifth-wheel trailer from Ellis, who allowed the couple to stay with him for several weeks as they completed the rennovations, Ellis said. He is not charged in connection with Arnold-Boesiger’s death.

“I only knew them from selling them my camper and because of her bad health, I invited them to stay at my house while they prepped the camper and then one day she just didn’t come back with him,” Ellis said Tuesday.

Arnold-Boesiger lived with the autoimmune disease Lupus, her family has said.

“She was very laid back, very cool, super quiet,” Ellis said. “That’s what I would say.”

Tollway and cellphone records showed that Arnold-Boesiger and Van Duyn traveled to the Roscoe and Rockford area on a daily basis in her white Dodge Ram truck from October until mid-November, according to the release.

On Nov. 15, Van Duyn sent Ellis a text message claiming that Arnold-Boesiger had overdosed and went to the hospital, court records show.

”A search of hospitals in the Rockford area revealed that Michele Arnold-Boesiger had not been treated at a hospital,” prosecutors wrote. “He went on to say that he gave her personal items to Michelle Arnold-Boesiger’s mother and that Dean Ellis would not see her again.”

During the time the pair had been staying with Ellis, he never witnessed them fight, he said.

“I had no idea she was missing until [the police] called me and sat down with me and blew my mind,” Ellis said.

On Tuesday, Hanley said that Arnold-Boesiger was reported missing in November 2020. Holiday Hills Police Department records, however, show that the Arnold-Boesiger’s mother didn’t report her daughter missing to the department until Jan. 3.

Hanley declined to clarify Tuesday whether a separate report was filed with another agency in November. He also declined to say whether police had contacted Arnold-Boesiger’s family before the Jan. 3 report was filed.

“[W]e are bound by what is in the public record – the [probable cause] statement – and will not comment on evidence or aspects of the case beyond that,” Hanley said in an email Tuesday evening.

Piecing together the investigation

An Illinois Tollway camera image showed Van Duyn driving the white Dodge truck at 3:47 p.m. Nov. 15. In the photo, Arnold-Boesiger’s service dog Atticus was sitting in the passenger’s seat, where Arnold-Boesiger was seen in prior tollway videos, according to the release.

After Arnold-Boesiger’s death, Van Duyn used the woman’s phone to contact her friends and ex-boyfriends to ask for money, Hanley said.

Szymanski, the former boyfriend, said he received out-of-character messages from Arnold-Boesiger’s phone and social media accounts around the time of her disappearance.

“I hate to be right. I had suspicions,” he said. “There were a lot of red flags.”

Arnold-Boesiger’s debit card also was used on the suspected day of her death to purchase “odor-eliminating products,” gorilla tape and “heavy duty garbage bags,” according to the probable cause statement.

“Jonathan Van [D]uyn had at least one conversation with a friend during this time who asked about Michelle Arnold-Boesiger’s whereabouts,” prosecutors wrote in the probable cause statement. “Jonathan Van [D]uyn responded with statements like she is long gone and they agree she should ‘RIP.’ ”

Van Duyn currently is in custody in Walworth County, Wisconsin, where he faces unrelated felony charges.

Officers in that case arrested Van Duyn on Dec. 15 after they said he took his biological daughter from her Walworth County, Wisconsin, home.

The girl’s mother, Tiffany Gallinger, has said that Arnold-Boesiger came to her months before the 33-year-old woman disappeared and claimed she was being abused by Van Duyn.

Reached by phone Tuesday morning, Gallinger said she hopes Arnold-Boesiger gets justice.

“The only thing I’m hoping is that justice is brought for Michelle,” Gallinger said. “She deserves it.”

In early December – weeks after investigators now believe Arnold-Boesiger died – investigators located Van Duyn with his 10-year-old daughter at a remote location in Indiana, court records show. He had been traveling in Arnold-Boesiger’s white Dodge Ram and was staying in a trailer, according to the probable cause statement.

“The daughter said after being abducted by her father, Jonathan Van [D]uyn, began to cry and told her that he killed Michelle Arnold-Boesiger,” prosecutors wrote. “He said that he killed her for them and hid her somewhere safe.”

During a search of the trailer, officers and FBI agents discovered “memories” written on the wall of the trailer, several of which referred to Nov. 15, 2020, according to the probable cause document. Specific statements written on the wall and in one of Van Duyn’s journals claimed that Nov. 15, 2020, was the day he was “was finally free,” prosecutors wrote.

Van Duyn remained in Walworth County, Wisconsin, Tuesday morning.

He was transported there after McHenry County prosecutors dropped domestic battery charges against him in May. Officials said at the time said Van Duyn was under investigation in connection with the death of his former girlfriend, Arnold-Boesiger.

Van Duyn was scheduled to appear in McHenry County court in May for a trial by judge on multiple counts of aggravated domestic battery, domestic battery and criminal damage to property. Prosecutors, however, dismissed those charges, which named Arnold-Boesiger as the alleged victim.

Without her testimony, prosecutors didn’t have a strong enough case to convict Van Duyn of the 2019 domestic battery, McHenry County State’s Attorney Patrick Kenneally said at the time, adding that his office could choose to refile the charges within the next 18 months.

It was unclear Tuesday evening when Van Duyn might be returned to Illinois to face the most recent charges filed against him.