MILWAUKEE (AP) — A 64-year-old nurse has been charged in the killing of a 23-year-old cognitively impaired woman whose battered remains discovered at the edge of a cornfield in southeastern Wisconsin were for two decades known simply as “Jane Doe,” police said Friday.

Linda Sue La Roche was arrested Tuesday in the July 21, 1999, death of Peggy Lynn Johnson, a homeless woman whom La Roche took into her home in McHenry, Illinois, five years earlier. According to a criminal complaint, La Roche, who now lives in Cape Coral, Florida, admitted that she abused Johnson for years, and she was charged Thursday with first-degree intentional homicide and hiding a corpse.

Racine County Sheriff Christopher Schmaling said she waived extradition to Wisconsin.

According to the criminal complaint, a passer-by found Johnson’s beaten body while walking his dog. An autopsy showed she was malnourished, had been struck in the head shortly before death, and had a broken nose and broken ribs, some of which were broken after death and some that had been previously broken and were healing. The autopsy report shows she died from sepsis pneumonia due to infection from injuries she suffered during chronic abuse.