A convicted sex offender in jail on suspicion of violating his probation is considered a “material witness” in the homicide investigation of University of Wisconsin junior Brittany Zimmermann, according to court records.  

Local Madison television station WKOW-TV disclosed Monday documents seeking to revoke David Kahl’s probation that quote him revealing to police he entered a home near Zimmermann’s residence the day she was killed. 

The documents show Kahl identified two homeless men, “Hank” and “Mitchell,” who were breaking into houses and “running scams” on the day of Zimmermann’s death, WKOW reported.

According to the report, police are treating Kahl as a witness, not a suspect, and he helped police develop a sketch of one of the transient men. 

Madison Police Lt. Jerry Tomczak said he has not heard any new developments in the ongoing investigation. 

Documents disclosed by WKOW-TV show Kahl, 42, telling police the two men used drugs “at a crack house on Wilson Street” and then separated. 

“I also know they were going into houses that were unsecured and stealing things like cell phones and laptop computers,” Kahl wrote in a handwritten statement submitted to corrections officials. 

The station also reported the documents allege that Kahl entered a home on West Washington Avenue with a scam about a car repair to try to get money to buy crack cocaine.

UW students on Blair Street previously said a man solicited their apartments asking for money to fix a flat tire. 

Kahl’s record includes a second-degree sexual assault conviction in a 1993 case where he pleaded no contest and was sentenced to a year in prison. 

Zimmermann’s fianc? Jordan Gonnering, also a UW student, found her slain in the apartment they shared on 517 W. Doty St. 

Madison Police Department has not identified any suspects in the investigation.