Her body was found in a Wisconsin cornfield in July 1999, but her identity remained a mystery until November, two decades after the 23-year-old cognitively impaired woman was murdered.
[Ads /]
Linda La Roche, a 63-year-old nurse has been charged with murder in the death of Johnson.
RELATED: Nurse charged in 1999 cold case beating death of cognitively impaired McHenry woman found in Wisconsin field
In September, someone called police and claimed that La Roche, who now lives in Florida, was telling people she killed a woman when she lived in Illinois.
Johnson met La Roche at a medical center in McHenry, Illinois, where La Roche worked as a registered nurse in the 1990s. Johnson went there seeking help after her mother died. Her father and brother were also dead. Johnson was around 18 years old, cognitively disabled and homeless when she met La Roche, authorities said.
La Roche took Peggy in, then forced her to work as a housekeeper and nanny for her family. She also made her sleep in the home's crawl space.
[Ads /]
La Roche is charged with first degree intentional homicide and hiding a corpse. She has waived extradition to Wisconsin.
According to the criminal complaint, La Roche's children admitted to police they saw her abuse Johnson, and the suspect's former husband said he came home one day to find her dead on the floor.
Johnson's body was dumped in Raymond, Wisconsin, about 40 miles northeast of McHenry. Her body was exhumed in 2013 with the hope of using advancing technology to identify her. She was reinterred in 2015.
Authorities said she was exhumed once more as part of the investigation.
The Associated Press contributed to this report.