Convicted sex offender may be witness in Madison co-ed slaying
A convicted sex offender who's jailed for violating probation is now considered a material witness in the slaying of University of Wisconsin-Madison student Brittany Zimmermann.
WKOW TV obtained documents which seek to revoke David Kahl's probation.
The station said Kahl is not regarded as a suspect. He reportedly told police he entered a house near Zimmermann's apartment the day she was killed near Madison's downtown on April 2. And he knew two homeless men named Mitchell and Hank who broke into houses and stole cell phones and laptops.
He said the pair also tried to con people into giving them money to buy crack by claiming they needed the cash for car repairs.
The TV station said Kahl also helped police create a sketch of one of the men.
Madison Police have targeted transient men in their investigation into Zimmermann's death.
They arrested about two dozen of them for various offenses since the killing and they hope DNA evidence will link a suspect to the victim.
Police have not said how Zimmermann, a medical student from Marshfield, was murdered.
Media reports said she was stabbed.
Officials said a man was caught entering a nearby house just before the killing.
But police are not commenting on the latest development.
Kahl was convicted of sexual assault in 1993. The TV report said he broke his probation by not registering as a sex offender.