Jackson Twp. man pleads guilty but mentally ill to killing wife

Angela Knoll-Dunn, who gave birth at 14, didn't meet her daughter, Diana Ziegler, until 2010, nearly two decades after she was born.

The two knew each other for six years before Diana Ziegler was killed by her husband, John D. "Jack" Ziegler, in January 2017.

John Ziegler III

On Monday, Oct. 29, Knoll-Dunn read a statement at John Ziegler's guilty plea hearing. During her reading, she held up a picture of her daughter and demanded he look at the photo.

"Look what you took from us, Jack," she said through tears. "Why Jack? Why did you do this?" 

On Monday, John Ziegler III, 33, of Jackson Township, pleaded guilty but mentally ill to first-degree murder and first-degree murder of an unborn child.

The prosecution and the defense agreed Ziegler was mentally ill when he killed his pregnant wife in their Jackson Township home. 

He killed Diana Ziegler, 25, with a scimitar-style sword on Jan. 27, 2017, at their Ledge Drive home, police have said. Diana Ziegler was 24 weeks pregnant at the time.

John Ziegler was sentenced to two consecutive life sentences without the chance of parole. 

Diana Ziegler, killed by her husband John Ziegler III in January 2017, is honored at a tribute concert to raise awareness for domestic violence on Jan 5, 2018.

As a result of John Ziegler's plea, prosecutors agreed not to seek the death penalty. The remainder of his charges were dropped as well.

More:Insanity defense for York County man accused of murdering pregnant wife

More:Tribute concert to remember slain pregnant woman

More:Neighbors hold vigil for slain Jackson Twp. mother

'Immeasurable loss': During Monday's hearing, Knoll-Dunn was one of three people who addressed the court.

Lisa Heilner, Diana Ziegler's stepmother, spoke on behalf of Diana Ziegler's father, Gerald "Jerry" Heilner, because the psychological toll would be too much, she said. Gerald Heilner lost his wife to multiple sclerosis about 10 years ago. He and his late wife adopted Diana Ziegler when she was born, and she was his only child.

"He is a person who has suffered an immeasurable loss," Lisa Heilner told the court.

Lisa Heilner described her stepdaughter as someone who cared for all and noted that she played cello and was a nurse.

"She looked for the best in people, including Jack," she said.

Lisa Heilner read a note written to her and her husband in 2013, after Diana Ziegler and John Ziegler had gotten back together after a period apart. In the note, Diana Ziegler mentioned that she had thought about the decision before getting back together and that the two were working to not repeat mistakes.

"I love him, and I am happy," Lisa Heilner read from her stepdaughter's note.

Diana Ziegler, she said, mentioned that John Ziegler was always asking her what he could do to be accepted by her family.

Diana Ziegler was expecting a baby girl, who was going to be named Charlotte, Lisa Heilner said. Diana Ziegler had just painted the girl's room two days before her death, she said.

"All of that was lost when Diana was taken from us," she said. 

Lisa Heilner asked the court to make it so John Ziegler never has contact with his young son, who was 2 at the time of his mother's death.

Diana: Mary Antes, a family friend who said she considered Diana Ziegler a daughter, told the court she promised Diana Ziegler's adoptive mother she would keep her daughter safe before the woman died of multiple sclerosis.

She said Jan. 27, 2017, was the worst day of her life.

"I felt like I had broken a promise I had made to her mother," she said.

Antes recalled going to the doctor's office with the Zieglers the day of Diana Ziegler's death. She watched their 2-year-old son while Diana Ziegler had an ultrasound done.

She said she never saw anything to indicate what would happen later that day.

Antes also noted that both John Ziegler's family and Diana Ziegler's family are affected by her death.

"(John Ziegler's) other children will never have a father again or their stepmother, who they were very close with," she said.

Antes said her daughter was very good friends with Diana Ziegler. Antes also said that she helped Diana Ziegler get in contact with her birth mother.

"She was just a wonderful blessing in my life," she said.

Knoll-Dunn told the court that she had trusted Diana Ziegler's adopted parents to protect her. When Diana and John Ziegler got married, her adopted parents then trusted John Ziegler to protect her.

"Which turned out to obviously be something you couldn't do," she said.

Knoll-Dunn said she made many memories with her daughter, but she should still be making more of them. Unlike John Ziegler, she will continue to make memories with her grandson, she said.

Knoll-Dunn said at some point she will have to forgive John Ziegler.

"That day isn't today, Jack, it isn't today," she said. 

Murder: Officials have said John Ziegler killed his wife with a 4-inch-wide scimitar-style sword on Jan. 27, 2017. 

He called 911 shortly before 4 p.m. and announced that he had killed his wife, according to police. 

Authorities responded to the scene and found her dead on the back deck of their home. She suffered multiple blows to her head and neck, and police also said they found her blood and skull fragments on the deck.

John Ziegler was arrested at the scene. The Zieglers' 2-year-old son was at the home but wasn't injured.

During the preliminary hearing last year, Northern York County Regional Police Detective Mark Baker testified that John Ziegler said he believed the world was being controlled by hybrid humans and that his wife needed to be killed because she was the "queen bee" of those hybrids.

Northern Regional Detective Robert Ryman also testified during John Ziegler's hearing, and he said that John Ziegler wasn't crying, was cooperative and was acting "very normal."

Both the defense and prosecution submitted psychological evaluations of John Ziegler, which Common Pleas Judge Harry Ness said showed John Ziegler was mentally ill at the time of the killing.

John Ziegler told the judge he is taking anti-psychotic medication.

His attorney, Jay Abom, told the judge that had John Ziegler known about his illness before his wife's slaying, he would have sought help.

John Ziegler told the judge that not a day goes by that he doesn't regret what he did. He apologized to everyone affected.

"Especially Diana's family — I'm sorry," he said.

— Reach Christopher Dornblaser at cdornblaser@yorkdispatch.com or on Twitter at @YDDornblaser.