Wilbert Thomas, 65, of Racine was arrested Saturday on charges of first-degree intentional homicide, robbery by use of force and two counts of bail jumping, the Milwaukee Journal Sentinel reported.
In 1999, prosecutors missed by three days a deadline to have Thomas declared a sexually violent person and held indefinitely in a secure mental facility, the newspaper said.
Police would say only that they arrested a 65-year-old man in the killing of Sandra Teichow, 67, of Lake Geneva, who was found dead in a parked car in Racine Thursday. Jail records show Thomas to be the only 65-year-old in custody on the homicide charge, the newspaper said.
A person called police after noticing Teichow inside a vehicle Thursday afternoon, Racine police said. They did not say how she was killed.
Thomas is a registered sex offender who was convicted of second-degree sexual assault in 1992, a state registry says.
He was charged this year with violating registry rules. Thomas was in court Oct. 8 on one of those charges but remained free on a $2,500 bond.