Complaint: Witness testimony, DNA match help MPD make arrest in Brittany Zimmermann case


MADISON, Wis. — Police have arrested a man in the 2008 death of Brittany Zimmermann, a college student killed in her downtown Madison home.

The Madison Police Department said 53-year-old David A. Kahl was charged with party to first-degree intentional homicide with use of a dangerous weapon.

According to a criminal complaint released Friday, Zimmermann’s boyfriend arrived home from class April 2, 2008 to find the outside security door of his apartment building broken and the door to his unit unlocked. He called 911 around 1 p.m. after finding Zimmermann lying on the floor of their shared apartment.

‘Every single day’: Family of Brittany Zimmermann looks for answers 10 years after unsolved murder

The complaint indicates multiple witnesses called police April 2 to report interactions with a stranger asking for money starting at 11:30 a.m. until early afternoon.  The witnesses all lived or were near 517 W. Doty St., the address of Zimmermann’s apartment.

In most cases, the witnesses said a man approached them asking for $40 or a ride to his house on the west side of town. According to the complaint, the man would tell people he and his wife needed money to fix a flat tire and his car was at a nearby mechanic. In one case, a woman said Kahl knocked and entered her home without permission before asking for money.

Some of the witnesses were shown photos and asked to point out the man asking them for money. Several people identified the stranger as David A. Kahl, according to the complaint.

One woman who identified Kahl as a man who knocked on her door asking for money told detectives “it was a day she would never forget,” the complaint said. Another witness said Kahl left his Wisconsin Department of Corrections Offender ID card in exchange for $20.

According to the complaint, police made contact with Kahl at his home on the 100 block of Franklin Street around 6:11 p.m. April 2 and brought him to a police station for questioning. Kahl admitted to being in the area of W. Washington Ave. that afternoon in order to get money. He also admitted to leaving his DOC ID with someone, the complaint said. Kahl denied going into homes and said he used the money to buy crack cocaine.

Kahl also said he was with a woman named Dawn while in that area and two men.

Detectives questioned Kahl again on April 7, 2008. During this interaction Kahl said he had been released from prison four months prior. He said he lived in a halfway house for about a month before moving into his apartment on Franklin Street. Kahl also told detectives he was diagnosed with paranoid schizophrenia a few years before and was off of his medication, the complaint said.

Kahl once again admitted to being high in the area and trying to scam people out of money. He said he and a Dawn rang “nearly all the doorbells on West Doty Street” and she wanted to go back to the area to rob people.

Detectives questioned Kahl again on April 8. During this interaction, Kahl said he had not forced his way into any apartments on April 2. He told detectives he was invited inside and offered a soda.

Kahl gave his fourth statement to police several months later on July 2 while he was an inmate at the Fox Lake Correctional Institution. Kahl once said he was in the downtown area to solicit money and purchase crack cocaine. He also mentioned being with Dawn and two other men.

During their time together, a detective specifically asked Kahl if he had been at Zimmermann’s apartment that day. Kahl said it was likely since they had gone to almost every home on W. Doty Street but said he could not remember if anyone answered at Zimmermann’s residence.

Kahl stated he was concerned his DNA or fingerprints would be on the doorbell of her home, the complaint said.

Detectives spoke with Kahl’s mother in July of 2008. According to the complaint, Kahl’s mother said there “is a night and day difference” in her son’s personality when he uses drugs and alcohol.

Detectives were contacted by another inmate at Fox Lake Correctional Institution toward the end of 2008.”The inmate said Kahl admitted he had broken into Zimmermann’s home and chocked her, the complaint said.” The inmate said Kahl was worried that his DNA would be on her body.

Kahl was questioned by detectives several years later in October 2011. During this interaction, detectives said they had DNA evidence that put him inside of Zimmermann’s apartment.

Kahl said he did not know what that would be about unless he had burglarized her home earlier that day or in the past. He also said he had helped two men burglarize homes on April 2, saying “sometime they looked out, sometimes I looked out.”

Detectives said Kahl asked what his DNA was found on. Detectives told Kahl it was an item belonging to Zimmermann. According to the complaint, Kahl responded with “I shook hands with people, too, that day” and said he gave a girl a hug too.

Kahl’s mother shared more information with detectives in 2014, according to the complaint. She stated Kahl said Zimmermann had given him money and a beer. She also said Kahl told her in 2010 he was not part of Zimmerman’s death, according to the complaint.

Kahl was questioned for a sixth time about Zimmerman’s death in December of 2014. During this interaction, he told detectives he believed two black men and Dawn committed the crime. Detectives said Kahl’s accounts differed from April 2, when he described one of the men he was with as being white, with a ponytail and tongue ring.

Detectives also asked Kahl if he had been given a beer inside Zimmermann’s house. According to the complaint, Kahl responded with, “I can’t remember, I was in so many houses. I was so f—– up.”

A couple days later, Kahl’s mother said she had more information about the murder. She told police she would talk with Kahl about the homicide every year on April 2. Kahl told her the guys he was with that day murdered Zimmerman. She also recounted their conversation from 2010, where he cried while admitting he did not kill Zimmermann.

Kahl’s mother also said he was worried he would be considered an accessory to a crime and told her he was “geeked most of the time” and doesn’t remember things about that day anymore.

In February 2016, detectives talked with a man that lived in the halfway house with Kahl. The man said he and Kahl got into a fight and Kahl said “I’ll do you like I did her,” according to the complaint.

In July 2016, a woman said she had talked with an acquaintance about the murders. The woman told detectives Kahl had mentioned he had interacted with Zimmerman in the past and that he knew the people who killed her.

DNA evidence was collected off Zimmermann’s body and clothing, but testing results had come back inconclusive until Feb. 12, 2020. According to the complaint, new testing results found Kahl’s DNA on Zimmermann’s jeans.

Kahl is a registered sex offender connected to a second-degree sexual assault conviction in 1993. Kahl is an inmate at Oshkosh Correctional Institution on an unrelated conviction and could be released as soon as November 2021, according to state Department of Corrections records.

Zimmermann was a Marshfield native studying medical microbiology and immunology.