Serial killer could have caused Harvard woman’s death in 1999, expert witness for convicted murderer says

Linda La Roche listens as her attorney Laura Walker delivers her closing argument during a hearing for a new trial on Feb. 26, 2024. La Roche was found guilty in March of 2022 for the murder of Peggy Lynn Johnson-Schroeder in 1999 and for concealing her corpse.

A pathologist testified Monday for a former McHenry County woman who is serving life in prison for killing a 23-year-old Harvard woman in 1999, saying her murder could have been the work of a serial killer.

Linda La Roche, 68, is serving life in prison for the murder of Peggy Lynn Johnson-Schroeder, whose bruised, burned and battered remains were found July 21, 1999, on the side of a road in Raymond, Wisconsin.

La Roche is claiming that she had ineffective counsel and should be given a second trial because her trial attorneys did not present evidence pointing to the death of another apparent homicide victim, Mary Kate Sunderlin. Her battered remains were found in a Lake County field about six months after Johnson-Schroeder’s were discovered.

La Roche’s attorney, Laura Walker, said Monday that “it is unreasonable that they didn’t even try to investigate the other murder.”

Johnson-Schroeder was a live-in nanny for La Roche and her family in homes in McHenry and Lakemoor for about five years before her death. She was known for 20 years as a Jane Doe until she was identified and La Roche was arrested. La Roche was living in Florida at the time.

Dr. Lindsey Thomas, a forensic pathologist hired by La Roche’s attorney for $400 an hour, testified Monday in a Racine County courtroom as part of La Roche’s efforts to win a new trial. Thomas said there was a “strong probability” the two women’s deaths were caused by the same person or people, including possibly a serial killer.

Witness Dr. Lindsey Thomas looks over an autopsy report as she answers a question during Linda La Roche’s hearing for a new trial on Feb. 26, 2024. La Roche was found guilty in 2022 for the murder of Peggy Lynn Johnson-Schroeder in 1999 and for concealing her corpse. La Roche was sentenced to life in prison without parole for the murder, and a consecutive five year sentence on the concealing a corpse charge. Johnson-Schroeder was known as Jane Doe until her identity was discovered when LaRoche was named as the suspect in the case.

Thomas, who is now retired, has performed thousands of autopsies and was involved in two investigations involving serial killers. She said both women suffered blunt force trauma to their heads, chests, abdomen and back, as well as on or near their genitalia. They also had a similar physical appearance and suffered similar abrasions, wounds and burns in various stages of healing.

Sunderlin’s cause of death was blunt force trauma, according to the autopsy. Johnson-Schroeder’s cause of death was blunt force trauma and sepsis, according to her autopsy.

Thomas also said both women were cognitively impaired and their remains were left the same way: on the side of a road “as if they had been deposited there.”

They each had pneumonia, “suggesting prolonged confinement,” she said.

On cross-examination, Assistant District Attorney Diane Donohoo pointed out that the women were not so similar in size and appearance and did not have exact injuries. Donohoo also said that La Roche’s trial attorneys were not ineffective but chose a trial strategy in not presenting evidence of any connection to Sunderlin’s murder.

The prosecutor challenged Thomas’ expertise in the area of profiling and serial killers. Donohoo asked whether in reaching her conclusion Thomas reviewed all the evidence, including recorded statements in the case, to which Thomas said no.

Thomas said the question she was asked to answer in this case “was quite narrow,” and she was only asked to compare the two autopsies and photographs.

It initially was thought that Sunderlin, 34, was the victim of an “unnamed duo” committing fraud against disabled people, and she had been sex trafficked, according to a court motion filed in La Roche’s case.

An arrest and conviction were made in the case but later overturned on appeal. Sunderlin’s case remains unsolved, according to Walker and news reports.

The attorneys also debated how C-shaped or loop marks on both bodies were made and whether they were the same size or caused by the same instrument. Thomas said the markings and other injuries were “remarkably consistent” with one another, “strongly suggestive they were inflicted by the same person.”

Donohoo responded that Thomas is “not an expert on tool marks” and there were no measurements taken of the markings on either body.

Doug Kelley, deputy chief medical examiner for Milwaukee County, testified as an expert for the state. He said there is no scientific way to give an opinion that the killing was done by a serial killer or what weapons were used to cause the injuries or who caused them.

There are “a lot of instruments that can cause those individual injuries,” Kelley said.

Kelley acknowledged that both women suffered blunt force trauma; however, he noted that blunt force trauma is “fairly common in autopsies.”

He also testified that although he would not say human remains being left on the roadside is “extremely common,” he has seen it happen.

At one point during the hearing, Donohoo said that if Thomas “thinks the same person killed both women, you cannot rule out that Linda La Roche killed both women.”

Prosecutor Diane Donohoo delivers her closing argument during Linda La Roche’s motion hearing for a new trial on Feb. 26, 2024. La Roche was found guilty in 2022 for the murder of Peggy Lynn Johnson-Schroeder in 1999, and for concealing a corpse. La Roche was sentenced to life in prison without parole for the murder and a consecutive five-year sentence on the concealing a corpse charge. Johnson-Schroeder was known as Jane Doe until her identity was discovered when La Roche was identified as the suspect in the case.

”We have to apply the actual law, not her opinion,” Donohoo said. “There was a chosen strategy in [La Roche’s] defense. … No matter how much she doesn’t like it, it was strategy. Her attorneys thought they could poke enough holes in the state’s case. They didn’t, but that was their strategy. That does not mean they were [ineffective] and she gets a new trial.”

Judge Timothy Boyle did not give a ruling Monday and did not set a date for when he would.