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.

He did not elaborate on the abuse but said, “the utter barbaric brutality inflicted on this young woman is something that none of us will ever forget.”

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.

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.

“Year after year we plugged away at this case,” the sheriff said. As a Jane Doe, Johnson’s DNA was entered into a nationwide unidentified victims’ database, her DNA was submitted for genealogical testing, and her body was exhumed for chemical isotope testing, he said.

“A number of weeks ago” information led to Johnson’s identification, the sheriff said, though he did not elaborate on what that information was.

Arrangements will be made for Johnson to be laid to rest as her true identity and buried alongside her mother, the sheriff said.