On Wednesday 1 March 2006 Brendan Dassey confessed to lead investigators Tom Fassbender and Mark Wiegert that Teresa had been shot in Steven Avery’s garage with Steven’s .22 caliber rifle. That same day personnel of Calumet County and the DCI returned to the garage for a 2-day search.
On Thursday 2 March, the second day of this particular search, special agent Kevin Heimerl of the DCI was searching the garage when at one point he looked under a green compressor and, utilizing a flashlight, found what appeared to him to be a bullet.
On 14 March 2006 the bullet was sent to the Wisconsin State Crime Lab by Calumet County deputy Jeremy Hawkins where it was to be examined by DNA Technical Unit Leader Sherry Culhane for the presence of DNA and by ballistics expert William Newhouse.
Culhane's test results
The bullet arrived at the laboratory on Thursday 16 March, and Culhane took custody of it 12 days later, on Tuesday 28 March.
Culhane began with a visual examination, but saw nothing visual on the bullet. That does not mean there is no trace evidence on the bullet, so in order to remove any residual DNA on the bullet, she washed it. She put the bullet in a test tube and washed it with some buffer that they use to extract DNA. The result of this procedure, a liquid, was what Culhane performed the rest of her testing on.
Culhane managed to develop a DNA profile from the washing result. She compared this DNA profile with that of a pap smear of Teresa and concluded the profile on the bullet is consistent with all of the types from Teresa.
Newhouse's test results
Culhane's contamination of the control sample
During trial it was pointed out by defense attorney Jerry Buting that Sherry Culhane, DNA Technical Unit Leader for the Wisconsin State Crime Lab who had examined the bullet, had contaminated a control sample and because of this, according to protocol, the bullet should not have been allowed into evidence.
Culhane explained she accidentally brought her own DNA into the control sample that she used to determine whether the equipment and instruments she was about to use on the evidence sample (a sample extracted from the bullet), and not contaminated already, from for example a previous test. The control came back blank, but as she extracted the blank control she talked to her students and that caused her own DNA to get into the control sample. However, it does show that the equipment was clean, and even if it was contaminated, it would've been with her own DNA.
When the equipment was used to test the evidence sample, a new DNA profile was found. One that wasn't in the control sample. The DNA profile of Teresa.
James Lenk arriving on the scene in March
In March James Lenk arrived on the scene, uninvited and not requested, while officers were searching the garage. Defense raised questions as to why Lenk would invite himself on the property on such a day, and why two bullets were found while he was somewhere on the property.
Lenk explained at trial that he never participated in any search that day, nor did he enter any buildings. He was there to give them rations or help in other ways unrelated to the actual investigation. Lenk was never seen inside the garage those days.
- ↑ CASO Investigative Report, page 706
- ↑ 2.0 2.1 2.2 2.3 Trial Transcripts day 10, Testimony of Sherry Culhane
- ↑ Trial Transcripts day 9, Testimony of Gary Steier
- ↑ Trial Transcripts day 9, Testimony of Kevin Heimerl
- ↑ CASO Investigative Report, page 717
- ↑ 6.0 6.1 Trial Transcripts day 10, Testimony of Sherry Culhane