Decades of Doubt: DNA, an Exhumation and an Acquittal in a 1992 Wisconsin Double Murder

For more than three decades Heather Thiel believed her father, Jeff Thiel, was responsible for the brutal 1992 slayings of Tim Mumbrue and Tanna Togstad. Her certainty led her to repeatedly press investigators — but advances in forensic genealogy eventually pointed to a different family member, triggering an arrest, a contested trial and an acquittal that left the family without the clear answer Heather had sought.

The crime and early investigation

On March 21, 1992, Mumbrue, 34, and Togstad, 23, were found dead inside Togstad’s farmhouse. A forensic pathologist later testified that Mumbrue had been stabbed dozens of times and his throat cut; Togstad had been stabbed once and showed signs of sexual assault. Even Togstad’s terrier, Scruffy, had been fatally stabbed.

Investigators initially considered several suspects, including Jeff Thiel, who Heather and others described as abusive and volatile. Thiel, who worked in a foundry and kept knives, died by suicide in 1995 after a violent traffic encounter with police. In 1996, as DNA testing was becoming more sophisticated, a semen sample linked to the scene did not match Jeff Thiel, and investigators moved on.

Renewed attention, genealogy and a new suspect

Heather was unaware of the earlier DNA exclusions and continued to tell anyone who would listen that her father was likely the killer. In 2010 she contacted authorities after seeing a billboard asking for tips. She again raised concerns about her father’s temperament and behavior, but investigators said they already had excluded Jeff from the semen evidence.

More than a decade later, Heather and her mother provided buccal swabs and access to a family tree that had been assembled on a genealogy website. In April 2022 investigators ran the crime-scene DNA through modern databases and identified a familial match inside Heather’s extended family. The unknown profile matched her cousin, Tony Haase, who worked at the same iron foundry and had no prior criminal record.

Investigators later secured Haase’s DNA covertly and said it matched the evidence from the crime scene. When confronted, Haase denied involvement at first but then described fragmented memories — "little clicks" — and details that investigators said were consistent with the scene, such as recalling a barbell and vomiting after leaving the house. Haase told investigators he had been drinking that night and thinking about an accident that had killed his father and involved Togstad’s family.

Arrest, legal fight and exhumation

Haase was arrested in August 2022 and later charged with the murders. As the case moved toward trial, his defense lawyers sought to argue that Jeff Thiel remained a possible suspect because some blood evidence had not been fully tested against his genetic profile. Prosecutors asked to exhume Jeff Thiel’s remains to complete additional testing aimed at definitively excluding him from the blood evidence.

In June prosecutors completed targeted testing and reported that Jeff Thiel was excluded from the available blood evidence. But a judge ruled that because the defense had not had adequate time to respond to the new testing before a trial set to begin, the state could not present the post-exhumation DNA results at trial if it proceeded as scheduled. Rather than delay a complex, decades-old prosecution, prosecutors elected to go forward without that evidence.

Trial and acquittal

At trial the defense argued Haase’s statements were coerced and that the male DNA found on Togstad’s body had degraded over years of testing and storage. Defense attorneys also reasserted the theory that Jeff Thiel — described by family members as an abusive, dangerous man — remained a plausible suspect. Prosecutors countered that the DNA evidence had been properly preserved and tested and described the defense’s alternative theory as a distraction.

After nearly a month of testimony and four days of jury deliberations, Haase was acquitted of the murders. The verdict left family members divided and Heather Thiel returning to her long-held belief that her father was responsible. "I wish there was a definite answer," she said. "Now, I feel like we still don’t know for sure. Until proven otherwise, I will always believe it’s my dad."

Aftermath and wider implications

The case highlights both the power and limits of modern forensic genealogy. The technique produced a family lead and an arrest in a cold case, but courtroom disputes over degraded evidence, investigative methods and the timing of new testing complicated the search for closure. For the victims’ families and for Heather Thiel, the acquittal underscored that even when science points in one direction, the criminal-justice process and human memory can leave painful questions unresolved.