A convicted sex offender jailed on suspicion of violating his probation is considered a material witness in the death of 21-year-old UW-Madison student Brittany Zimmermann, court records show.
Documents seeking to revoke David Kahl’s probation quote him as telling police he entered a home near Zimmermann’s apartment on the day she was killed and knew two homeless men he identified as “Hank” and “Mitchell” who were running scams and breaking into houses, WKOW-TV reported.