Mugshot on left David Kahl and Brittany Zimmermann
David Kahl is a registered sex offender who now stands accused in the 2008 stabbing and strangulation homicide of Brittany Zimmermann, a University of Wisconsin-Madison college student whose body was found in her apartment.
The criminal complaint makes it clear that Kahl was on authorities’ radar from the start, and they’ve allegedly had DNA evidence tying him to Brittany’s clothing for years. In repeated interviews with police, he described hustling young female college students for money to feed a crack cocaine addiction, saying he would knock on their doors and falsely claim that his car broke down, and he needed $40, the complaint contends. It also alleges that he admitted being inside Brittany’s apartment but claimed other homeless people committed the murder in a series of conflicting statements over the years.
“Criminal charges were filed today in the murder of Brittany Zimmermann,” a statement from the Madison, Wisconsin Police Department read on March 20, 2020. “David A. Kahl, a 53 year-old male, has been charged in Dane County Circuit Court with First Degree Intentional Homicide (as party to a crime and by use of a dangerous weapon).” Authorities have not explained why they chose to charge the case as party to a crime.
Brittany was killed on April 2, 2008 in her downtown Madison apartment. “Brittany’s killing shook the Madison community and devastated her family, friends, and hometown,” said the police statement. “It has been almost 12 years since Brittany’s death. During that time, MPD never gave up on her case, tirelessly pursuing justice for Brittany and her family.”
However, from the start, the case has involved questions about a 911 dispatcher’s handling of a frantic call from inside Brittany’s apartment, and why it took so long to charge Kahl due to the fact DNA and other evidence was developed years ago. Kahl’s name has circulated in the media for years, and, in 2016, Brittany’s parents confirmed a DNA match had been found in the long languishing case. However, it took until 2020 for charges to result.
Here’s what you need to know:
1. Zimmermann, a Microbiology Student Who Lived With her Fiancee, Died of Stab Wounds, Ligature Strangulation & Blunt Force Trauma
Zimmermann was a native of Marshfield, Wisconsin who was only 21 years old when she died. She was a student at UW-Madison who was majoring in Medical Microbiology and Immunology, according to the Madison police statement, which added, “She lived with her fiancee and their three cats in the 500 block of West Doty Street.”
Police added that investigators “have conducted hundreds of interviews, processed countless pieces of evidence, and produced thousands of pages of reports. The Dane County District Attorney’s Office and Wisconsin State Crime Lab have also been instrumental in the investigation. Investigators have conducted hundreds of interviews, processed countless pieces of evidence, and produced thousands of pages of reports.”
“The dedication and persistence of those tasked with investigating this case – past and present – has never wavered,” police wrote.
The criminal complaint, obtained by Heavy.com from the Dane County Clerk of Courts Office, says that, on April 2, 2008, at approximately 1:10 p.m., the City of Madison Police Department received an emergency dispatch and an officer responded to 517 W. Doty Street, in the City of Madison, Dane County, Wisconsin. Upon arrival at that location, he observed a male exit from apartment 1, talking on a cell phone. Officer Murphy reports that the male, later identified as J.G., Brittany’s fiancee, indicated that he was speaking with dispatch. Officers entered the residence and observed a female laying on the floor, with apparent injuries to her chest area. She was unconscious, non-responsive and pulseless. She was pronounced deceased at the scene.
The complaint graphically describes the crime scene. Be aware that the details are very disturbing. Brittany resided at 517 W. Doty Street, along with her boyfriend, J.G., the criminal complaint says.
“Deputy Coroner Sholts reported that the manner of death of B.Z. was deemed to be homicide and that the cause of death was a combination of sharp force and blunt force injuries…the Madison Police Department received the Medical Examiner’s Autopsy report, authored by Dr. Robert Corliss. Dr. Corliss reports that he conducted the autopsy of B.Z. on April 3, 2008. The final anatomic diagnosis was ‘complex homicidal violence,’ including multiple sharp force injuries, evidence of ligature strangulation and blunt force injuries.”
According to the complaint, Dr. Corliss “reports that there were multiple stab wounds to the anterior chest. Dr. Corliss reports that there was a horizontal band consistent with ligature marking over the anterior neck, and surrounding the ligature mark were ‘superficial punctate hyperemic markings’ consistent with excoriations. Dr. Corliss reports that one side of B.Z.’s face, extending from the forehead to the chin, sustained contusional injury.”
2. The Criminal Complaint Recounts Zimmermann’s Last Moments & Alleges That Witnesses Placed Kahl Near Her Apartment Complex That Day, Repeatedly Asking Strangers for Money
Where witness accounts allegedly put the defendant on the day of the homicide
The criminal complaint recalls how, on April 2, 2008, Brittany had “attended class on the University of Wisconsin campus and had left class at approximately 11:30 a.m., with a fellow student, R.M. Detective Esser spoke with R.M., who stated that after class, she and (Brittany) spoke briefly with the professor, then walked outside. R.M. stated that as they were walking on the sidewalk, a male on the deck of a building yelled out to (Brittany), holding his cell phone.”
The complaint further states that “R.M. stated that it seemed that (Brittany) knew the male and she walked towards him. R.M. stated that she left (Brittany) and continued on. R.M. stated that she assumed that (Brittany) was going to go home for lunch, as was her normal practice after that class.”
Police determined that, after lunch, Brittany went on her computer. “Detective Murphy reports that she performed an analysis of the activity on April 2, 2008 on the computer located in a bedroom at 517 W. Doty Street. Detective Murphy reports that at 12:00 p.m., a UW website regarding financial aid was opened and at 12:01 p.m., (Brittany’s) email account was accessed. Detective Murphy reports that it appears that (Brittany) was on her computer and online from 12:00 p.m. on, and was fairly active on the computer until 12:18 p.m., when the computer activity stopped.”
One minute later, though, a 911 call originated from Brittany’s phone.
“Detective Murphy reports that on April 2, 2008, she made contact with Supervisor Rick Lang at the 911 Dispatch Center, in Dane County, Wisconsin. Detective Murphy reports that he located a 911 call originating from the cell phone number belonging to (Brittany),” the complaint recounts. “The call occurred on April 2, 2008, at 12:19 p.m. Supervisor Lang stated that he had reviewed the dispatch tape of the call and that at the very beginning of the call, a female could be heard screaming. Supervisor Lang stated that he could then hear muffled sounds of voices and some activity before the call was disconnected.”
This call caused great controversy. According to Madison.com, police “were not notified of a disconnected call from Zimmermann’s cellphone” made around the time of the homicide. The dispatcher claimed she didn’t hear the screaming and sounds of a struggle on the call. The controversy led to changes in 911 procedures. According to Madison.com, a “mistake by dispatch center personnel who misread their recording system” gave police a “false lead” that slowed down the investigation for two weeks.
A detective later spoke with Brittany’s fiancee and roommate J.G., who stated that he had observed Brittany and a friend on campus earlier that day. He called out to her from a balcony and spoke to her by phone. He said she usually goes home after class. Horrifically, Brittany’s fiancee later discovered her body.
“J.G. stated that he attended his class from 12:05 p.m. to 12:55 p.m. and then rode his moped back to the residence at 517 W. Doty Street,” the complaint says. “J.G. stated that when he first approached the house, he noticed that the lock to the outside security door was broken. J.G. said it looked like somebody had kicked open the door. J.G. walked into the entry way and noted that the door to their apartment was unlocked. J.G. stated this was very unusual. J.G. walked from the living room back towards the bedroom and observed (Brittany) laying on the floor.”
He placed a 911 call at 1:06 p.m.
It soon emerged that numerous eyewitnesses had seen Kahl asking for money in the area that day.
According to the complaint, Kahl was present “near the homicide.” One witness was named as G.N. in the complaint. He said that he and his girlfriend lived in the area and he was taking his dog for a walk around 11:30 a.m. on the day of the homicide when he saw a man standing at the front door of the apartment complex near his girlfriend’s.
The man asked him for “$40 or a ride to his house on the west side of town. The male said that he and ‘his wife’ had a flat tire and had taken their car to a nearby mechanic. The male said the mechanic was going to charge $40 for the tire to be patched up. G.N. told the male that he did not have any money, but that after walking the dog he might give the male a ride,” the complaint said. “G.N. stated that the male then said that he would need to ‘check with my friend.’ G.N. observed that the male seemed to be ‘jittery.'”
He walked his dog around the block and then noticed the same man on the porch of another residence. He asked the man if he needed a ride and the man said he needed to go and let “his wife” know what was going on, according to the complaint. The man then walked westward on Wilson Street. He was then seen on another porch, shaking a man’s hand.
“G.N. described the male as being 40-45 years of age, with salt and pepper hair and stubble on his face. G.N. stated that the male was not wearing a hat and was wearing a darker color shirt. Detective Nale reports that he administered a sequential photo array to G.N. and that G.N. identified the defendant, David A. Kahl, as being the male subject who had approached and asked him for money,” alleges the complaint.
Another woman also spoke to police and stated that a man knocked on her door that day and claimed he had a flat tire and needed $40 to repair it. She told him she would ask her fiancee and he said he would return, which he then did, but the woman said she didn’t know if her fiancee had any money. She described him as frustrated. She identified the man as David Kahl.
Another witness described a man coming into the lobby of a radio station around noon and making a similar request. Yet another man told police that Kahl tried to “panhandle” from him in the area that day, according to the criminal complaint. Other witnesses provided police with similar stories.
Police said that Brittany’s parents, Kevin and Jean, “have remained heavily invested in the investigation, and communicated regularly with investigators, MPD leadership, and representatives of the District Attorney’s office over the years.
Police also released a statement from Brittany’s parents, “It is with mixed emotions that we write this statement today. First and foremost, we are grateful to the Madison Police Department and the Dane County District Attorney’s Office for not giving up on this investigation. It has been almost 12 years since we lost our beautiful daughter, Brittany, and we could not have gone through this without the love and support of our family and friends. To all of them, we are eternally grateful.”
The parents’ statement continued: “Having charges filed is just the beginning of justice for Brittany, which is what we have wanted from the start of this horrible tragedy. Nothing will bring our beautiful daughter back and we continue to feel that pain every day. Therefore, while we have appreciated all the community support throughout the past 12 years, we are respectfully asking for privacy during this difficult time. Thank you.”
3. Kahl Is Already Incarcerated in the Wisconsin State Prison System & He Gave a Series of Implicating Statements Over the Years Relating to Being at Brittany’s Apartment, But Blamed the Murder on Other People
Brittany Zimmermann
According to the Madison police, Kahl “is incarcerated in the Wisconsin Prison System for unrelated charges and will be transported to Dane County in the future.”
He is a registered sex offender already on a life time registry requirement, according to the Wisconsin Sex Offender Registry. According to Wisconsin court records, the case is a second-degree sexual assault with a habitual criminality penalty enhancer that dates to 1993. In 2016, he was convicted of 7th offense drunk driving. He received a three year prison sentence on that offense. He faced a slew of criminal charges over the years, including disorderly conduct and theft, and more serious charges, like felony drug dealing. He’s cycled through the Wisconsin prison system since at least 1992.
In an April 7, 2008 interview with police, recounted in the criminal complaint, Kahl allegedly said that “he had gotten out of prison approximately four months ago, had lived in a halfway house, and then had moved into his residence at 114 N. Franklin Street, apartment 1, in the City of Madison, approximately three months ago.”
He was accused of telling police that he “was diagnosed with paranoid schizophrenia approximately two to three years ago and is presently off his medication.”
His gave a series of police interviews over the years. In one, he claimed he was hanging out with other people who commit thefts and burglaries by calling through college kids’ windows when they aren’t home.
He stated that he was associating that day with a woman he was smoking crack with and two males who were with her. He stated that the woman told the two men they should return to the same area and obtain more money by robbing one of the college-aged females. It’s not clear from the complaint whether these three people really existed or whether police were able to track them down; however, they feature heavily into Kahl’s own stories of what happened that day, according to the complaint.
According to the complaint:
Kahl claimed that they smoked crack.
He claimed he saw the police response while walking with the woman. “I’m thinking they could have gone back there and robbed that girl,” he told police, according to the complaint.
On April 8, 2008, he gave another statement to police. He said he had not forced his way into apartments or forced women to give him money when he did his tire scam. He said some women let him come in, gave him soda, or let him use the bathroom. He said the other two men sold crack.
In a fourth statement to police on July 2, 2008, he stated that he went out twice to solicit money, ordered and smoked crack at his residence, and then would get more money. He stated he ran into the two men and they all started “working the W. Doty and W. Main Street neighborhood.”
He admitted it was possible he had been at Brittany’s residence that day because he had gone to every residence, but he said he wasn’t sure whether anyone answered. He said he was concerned his DNA or fingerprints would be on the doorbell because he did knock on the door.
His own mother told police Kahl was becoming “more and more verbally abusive when using crack cocaine.”
In December 5, 2008, an inmate at Fox Lake Correctional Institution told a police detective that the defendant told him he was worried about being charged in Brittany’ homicide. Specifically he mentioned “being worried about his fingerprints being on her skin, specifically her throat area.”
He stated that he had broken into Brittany’s residence and choked her and “that his prints might be on her throat,” but he did not admit to killing her. He said he was high on crack and “that he and others had a scam going,” alleges the complaint.
In 2011, Kahl was interviewed by police again. He was told DNA evidence had been developed. He again admitted, “I was out hustling that day” and said he had been smoking crack, the complaint says.
It further contends:
He now claimed he was standing outside a house acting as a lookout for the two males when they exited a house carrying a television. The detective told him that his DNA was found inside Brittany’s residence, and he said that he might have burglarized it earlier that day or in the past. He then said he didn’t really remember her house.
He asked what his DNA was on, and he said it was on an item belonging to Brittany and claimed, “that one girl I gave a hug, too.”
His mother allegedly told police her son told her that he had been at Brittany’s house that day but “the two colored guys or the white girl went back where the girl had died.”
He told her Brittany gave him money and a beer but claimed he left her apartment and didn’t murder her, the complaint says.
He allegedly told his mother that he knocked on Brittany’s door and told her he needed money. She had given him money and offered him a beer and ended up in her kitchen. He told her that the men were armed and went back to get money.
In 2014, he was interviewed yet again.
He again tried to pin the blame on the woman and two men he was with that day. This time, when asked if he had been to her house and been given a beer, he stated, “I can’t remember, I was in so many houses and I was f*cked up,” says the complaint.
In 2014, his mother told police that her son told her that the guys with him had wanted the defendant to show them the places that people had been “nice” and that he did go back with these guys and that’s when the murder happened. He claimed he didn’t witness the murder.
His mother was living in Milwaukee. She said her son would scam to get drugs.
He denied killing Brittany. “Then he told me that they went back. And now he kind of said that, ‘well I was there.’ And when they brought the gun and the knife out – I am out of here and he left, and he don’t know what happened after he left,” his mother allegedly told police.
He also allegedly commented that Brittany “was a very pretty girl and she did not deserve what happened to her and that she was nice.”
In 2016, a man who lived in a halfway house with the defendant allegedly stated that during a dispute about money, Kahl stated, “I’m under investigation for a homicide. I’ll do you like I did her.”
In 2016, a woman talked to police and claimed she spoke to the defendant about Brittany’s homicide. She referred to Kahl as “Kookie” because he did “goofy things.”
He told her he needed to get something off his chest. He claimed he had spoken to Brittany on several occasions, and he liked her. He claimed he gave Brittany a hug and left. But the guy he was with, some other homeless guy, went in to borrow money. The defendant said he heard screams and took off, the complaint says.
4. Authorities Have Had DNA in the Case for Years
A portion of the criminal complaint.
It’s clear that forensic evidence – specifically DNA – will be a big factor in the case. However, authorities have had that evidence for years.
Back in 2016, Brittany’s parents helped bring that revelation to light. According to NBC 15, concerns were raised about why charges hadn’t been filed but former Madison Police Chief Mike Koval said there was not “sufficient confidence in the DNA as evidence in and of itself.” That year he told Madison.com the case “is not ripe for arrest and referral.”
In addition, according to Madison.com, back in 2014, police also received information from a former roommate of Kahl’s, Andrew Scoles, “that Kahl had confessed to the killing.” Scoles wanted his own charges tossed in exchange for giving more information about that, though, and he has since died.
The Isthmus did extensive reporting on efforts, including by Brittany’s mother, to get Scoles to reveal what he knew.
The new criminal complaint details the DNA evidence in great detail.
Brittany’s fingernails were clipped. Her jeans and two shirts were recovered.
In 2011, authorities with the Wisconsin State Crime Lab reviewed a fingernail clipping taken from Brittany’s right hand. They amplified it and found that Kahl was “included as a possible contributor to the Y-STR DNA profile detected from Item R1.”
The profile was searched against 18,547 individuals in the US and was found to occur 3,713 times.
Brittany’s shirt was swabbed. There were profiles that are mixtures of DNA from three or more individuals. Kahl was included as a possible contributor to the DNA mixture profile from items BJ2 and BJ3, says the complaint.
At first, the DNA profile from the swabbing of the shirt sleeve was not eligible for entry into the Combined DNA Index System. However, FBI guidelines changed, and it was entered in 2014. “A search of this evidentiary profile against the Forensic and convicted Offender Indices revealed a candidate match between the evidentiary profile and the profile of a convicted offender in the Wisconsin DNA Databank. The personal information on record related to the matching offender profile of the defendant, David A. Kahl,” says the complaint.
In addition, a DNA profile that is a mixture of DNA from at least two male individuals was found and the major contributor was allegedly consistent with the defendant’s DNA. It was searched against 5,259 male individuals’ profiles in the US and was found to occur zero times.
In 2017, authorities forwarded the DNA to a Pittsburgh company called Cybergenetics. In 2018, a report came back stating that a DNA match was found between the right sleeve and the “defendant that is 226 thousand times more probable than a coincidental match to an unrelated Caucasian person. The chance of a false positive for this comparison is one in 12.7 million.”
A match was found between the left sleeve and the defendant that is 12.4 million times more probable than a coincidental match to an unrelated Caucasian person, the complaint added.
In 2009, a detective received a letter with a return address from prison. The writer indicated that he overheard an inmate named F.R. discussing how he was involved in killing Brittany.
The inmate was talking “about the murder of that girl… and how he and his friends killed her he was telling some other persons outside how he lived down the street from her.. he knew when she was home alone.. there (sic) plan was to rape her and rob her but thing’s went wrong.”
The detective removed the envelope from the evidence bag in April 12, 2019 and took it to the crime lab for DNA analysis. Kahl was the source of the DNA profile found in a cutting from the center of the adhesive sealed area of the envelope, says the complaint.
5. Kahl Is Accused of Telling Police He Had a ‘Crack Addiction’ & ‘Subsisted on Defrauding Downtown Residents, Generally Young Women’
A portion of the criminal complaint.
It wasn’t long after the homicide before police soon tracked down David Kahl. According to the criminal complaint, in his first interview with authorities, Kahl claimed that he “woke up around noon, watched soap operas, then went to try to borrow money for food. The defendant stated that he would go to people’s houses, ring the doorbell, then tell people he needed $40 for a spare tire. The defendant stated that he would use people’s cell phones and pretend to talk.”
He admitted being in the area near the homicide, the complaint contends. “The defendant admitted to being on the streets near W. Washington Avenue. The defendant stated that he gave his DOC card to another person and promised to come back to repay the money,” the complaint says. “The defendant stated that he used the money for crack and had no intention of coming back to pay anyone for the money. The defendant stated that he did not recall going inside anyone’s house.”
He’s alleged to have told police he had a “crack cocaine addiction and was high that day.” He claimed that, when he first got money that day, “he bought a rock (of crack cocaine), went home and smoked it, then went back out to get more money.” He also alleged that he stopped at a crack house. He allowed police to take his DNA. He had small cuts on his palm, according to the complaint, and he told an officer, “I wish I’d never gotten involved in this sh*t,” attributing it to “bad associations.”
He allegedly told police that he “subsisted on defrauding downtown residents, generally young women, out of money by surprising them in their apartments and fabricating a story about needing $40 to replace a flat tire. The defendant stated that this was easy to do because many of his ‘marks’ failed to lock their front doors.”
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