Kari Danser joined Cybergenetics as an intern fresh out of Duquesne University’s forensic science program. She was filling in for someone on maternity leave. Two years later, she’s a primary analyst on 89 cases, has testified three times in court, and recently helped build a statistical link between a suspect and a murder weapon.
Cybergenetics is a Pittsburgh-based company whose TrueAllele® probabilistic genotyping software interprets DNA mixtures that conventional methods can’t resolve. Crime labs, prosecutors, defense attorneys, and innocence organizations send the company their FSA or electropherogram data files; Cybergenetics analysts run those files through TrueAllele® and return statistical genotype results. They don’t touch the physical evidence. They work downstream, after the lab has done its processing.
Danser sat down at ISHI 36 to discuss her work, her path to the witness stand, and the case she calls her pride and joy: a 1963 cold case homicide from Oshkosh, Wisconsin, where degraded DNA from a moving blanket — tested multiple times over decades without resolution — finally yielded a statistical identification.
A Complement, Not a Replacement
TrueAllele® occupies a specific position in the forensic workflow. The crime lab does the wet work — extraction, amplification, capillary electrophoresis — and produces the data files. From there, those files can be sent to Cybergenetics by the lab, by a prosecutor, by a defense attorney, or by an innocence organization. TrueAllele® takes the mixture data and uses probabilistic modeling to separate contributors and calculate match statistics.
The software is validated to handle mixtures of up to ten unknown contributors. In two years, Danser has personally seen a seven-person mixture.
The model works because it doesn’t force a binary call. TrueAllele® separates the STR data into individual contributor genotypes and computes a likelihood ratio — an inclusionary or exclusionary statistic that analysts can then take to court.
Testifying to the Statistics
Danser has testified three times. The first two cases resolved quickly — one a prosecution where the defendant was statistically excluded, one a defense case where no comparison could be made because the defendant’s DNA was never submitted. Both were short appearances. Both ended in guilty verdicts reached on other evidence.
The third case was different. A firearm connected to a murder. A defendant whose DNA was present on that firearm — statistically.
“There was an individual that was connected to this firearm that was a murder weapon, and we included him. Statistically, his DNA was present on this firearm and they found him guilty.”
Preparation for testimony runs through Cybergenetics’ chief scientific officer, Dr. Mark Perlin, who Danser credits with building the training framework analysts use before they go on the stand.
The 1963 Case: Evidence That Waited Sixty Years
On the night of June 13, 1963, a gas station owner named Wayne Pratt was found stabbed more than 50 times in a storage room and covered with a moving blanket. Investigators questioned 75 people, administered 25 lie detector tests, and turned up nothing solid. The case went cold.
In 2012, Winnebago County reopened the investigation. The blanket was sent to a local crime lab for DNA testing. Results were inconclusive. Private labs retested in 2015 and 2023, identifying a degraded, low-level mixture of multiple contributors — but couldn’t interpret it. In April 2024, the Sheriff’s Office sent the data files to Cybergenetics.
Danser worked the case. TrueAllele® separated the mixture into three distinct contributor genotypes. One matched the victim. One matched his wife, who had uncovered the blanket when she found him. The third matched a named suspect: William Doxtator.
“This is from 1963. DNA wasn’t around until the 80s. The fact that there was DNA still left on this blanket itself is a miracle, because it wasn’t stored properly. And then it was tested several times with several different kits, and we were able to actually link one of the suspects to the blanket.”
Cybergenetics issued its report in June 2024. The statistical link to Doxtator, combined with original case reports and witness statements, led the Sheriff’s Office to refer a charge of first-degree intentional homicide to the District Attorney’s Office. Doxtator had died in 2022. District Attorney Eric Sparr concluded that, had he lived, the new DNA evidence would have supported a homicide prosecution.
Wayne Pratt’s son was two years old when his father was killed. He remembers it. He now has answers sixty years later.
“I like making a difference with the forensic community. It’s awesome to help individuals solve cold cases and even get justice for those that — often times — you can’t.”
Danser also presented an oral session at ISHI 36 on pairing next generation sequencing with probabilistic genotyping to resolve complex DNA evidence — a methodology she sees as the field’s next step in addressing mixture interpretation at scale.
Watch her full ISHI 36 interview to hear her walk through the cold case, the testimony experience, and what working in probabilistic genotyping looks like two years in.