(CHICAGO) — A Jane Doe, who suffered “barbaric brutality” and was found dead in a Wisconsin cornfield 20 years ago, has now been identified and authorities say her suspected killer is in custody.The “brutally abused body” of 23-year-old Peggy Lynn Johnson was discovered on July 21, 1999, in a cornfield in the town of Raymond, about 75 miles north of Chicago, according to the Racine County Sheriff’s Office.The young woman was unidentified until now.Johnson had been brutalized “by many means” over a long period of time, Racine County Sheriff Christopher Schmaling said at a news conference on Friday. “The utter barbaric brutality inflicted on this young woman is something that none of us will ever forget.”According to the criminal complaint, her body “appeared slightly malnourished” and “had several suspicious marks, burns, abrasions and lacerations throughout.” She had blunt trauma to the head, post-mortem broken ribs, a broken nose, bruises and swelling from infection.Her cause of death was ruled homicide “by sepsis pneumonia as a result of infection from injuries sustained from chronic abuse,” according to the criminal complaint.Earlier in the ’90s, Johnson was about 18-years-old, cognitively impaired and on her own when she went searching for help at a medical clinic in McHenry, Illinois, the sheriff said. There she met Linda Laroche, a registered nurse, who recognized her disability and took her into her home, Schmaling said.Johnson, who was never listed as a missing person, lived in McHenry with Laroche for the last five years of her life, Schmaling said.”There she suffered long-term and horrific abuse at the hand of Linda Laroche,” he said.But, the suspect in the Jane Doe case was unknown for two decades. Then this September, Racine County investigators received a tip from saying Laroche “was telling people that she had killed a woman back when she lived in Illinois,” according to the criminal complaint.Investigators spoke with one of Laroche’s children and learned Laroche took Johnson in to work as a nanny and housekeeper in exchange for a place to live, the criminal complaint said.Investigators learned “Laroche was verbally and emotionally cruel” to Johnson, “at times screaming at her like an animal,” the criminal complaint said.Laroche allegedly slapped her in the head and face and allegedly stabbed her in the head once with a pitchfork, the criminal complaint said.”At times when not working for the family, Peggy would be made to sleep and stay in a crawl space under the home,” the criminal complaint said. Laroche’s former husband spoke with investigators this month and recalled that the last time he saw Johnson at their home, he found her “lying on the ground lifeless,” the criminal complaint said.He told investigators that his wife said Johnson “had overdosed and she was going to take her away from their house so they would not be involved,” the criminal complaint said.Investigators interviewed Linda Laroche this week during which she admitted to abusing Johnson. But “Laroche claimed that Peggy would steal, have men come to see her at their house, and that she would go into the crawlspace of their house to steal medications,” according to the criminal complaint.Laroche said one day Johnson was holding pills before she fainted. Laroche, a registered nurse, told investigators “she thought about calling an ambulance but didn’t,” the criminal complaint said.Laroche said Johnson eventually woke up and she “decided she couldn’t handle Peggy anymore and took her to a phone booth at a nearby gas station,” the complaint said. Laroche told investigators Johnson called her grandmother and she then “turned [her] over to her grandmother,” the complaint said.”When confronted with the fact that Peggy’s grandmother had been interviewed by police and said she had never met Laroche or her husband, Laroche later changed her story and admitted that she was not sure who the person was that she left Peggy with,” the complaint said.In another interview this week, Laroche changed her story, admitting to driving Johnson to Wisconsin, the complaint said.”Laroche admitted to letting Peggy out of the car in a rural area and leaving her by the side of the road,” the complaint said. “Laroche asserted that Peggy was not injured at all when she dropped her off and that something must have happened to her after she dropped her off.”Laroche was taken into custody Tuesday in Florida for Johnson’s murder, the sheriff said. She has waived extradition and will soon be transported to Wisconsin, he said.Johnson’s family was found and her identity was confirmed through familial DNA testing, according to the criminal complaint. Arrangements will be made for Johnson to be laid to rest as her true identity and buried alongside her mother, the sheriff said.Copyright © 2019, ABC Radio. All rights reserved.