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CHILTON Wis. - An analyst from the Wisconsin State Crime Lab was questioned about the credibility and reliability of the crime lab's work on an important DNA test in the Avery case. Steven Avery's attorney, Jerome Buting, spent most of Monday cross-examining Sherry Culhane.
Culhane is familiar with Steven Avery. She performed the DNA testing that freed Avery from prison in 2003 for a 1985 rape he did not commit. Culhane also helped wrongfully convict Avery on the same charge. She testified against him in the 1985 case using a hair analysis procedure she conducted. That 1985 hair analysis was wrong.
In the Halbach murder case against Avery, Culhane contaminated one of the tests with her own DNA. Culhane was testing a bullet fragment found in Avery's garage. The fragment tested positive for Teresa Halbach's DNA. However, Culhane's own DNA was found in a vial of "negative control" solution that should not have had any DNA in it. Culhane believes she was talking during the test and some of her saliva got into the "negative control." She explained that she was training new DNA analysts at the time.
The bullet fragment is an important piece of evidence because it is the only physical proof that Teresa Halbach was in Steven Avery's garage.
Using the results of a contaminated DNA test to prove that someone's DNA is present is rare. Culhane had to file paperwork because it involved a deviation from protocol. Attorney Buting asked her, "this is the only time in your entire career you have filed a deviation of protocol so you could make a call and include somebody, right?" Culhane answered that it was, in fact, the first time. Culhane has worked for the Wisconsin Crime Lab for 23 years and has been conducting DNA testing since 1996.
Buting used statistics to prove that Culhane has a high rate of contamination in her DNA testing work. "I see you're the highest contamination person in this log," he questioned. Culhane explained her record of contamination by saying that she conducts more tests than other analysts.
On Friday, Culhane confirmed that Steven Avery's blood was in numerous places inside Teresa Halbach's SUV. Culhane also said testing showed Halbach's DNA was found on a bullet fragment at the Avery property.
Buting also asked about Culhane's credentials. He pointed out that she does not have a master's degree. He told jurors that she has not written scientific articles for publication. Culhane countered by telling Buting she has more than twenty years of crime lab experience.
Check back here for updates throughout the day from TODAY'S TMJ4 reporter Mick Trevey, live in Chilton.
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BEFORE THE TRIAL:
