Item BZ

**Item BZ** are pieces of charred bone material with surviving tissue found in Steven Avery’s burn pit. It is the only soft tissue of Halbach that survived the fire. A DNA profile was obtained from the tissue, but due to being exposed to intense heat the profile was no longer complete. Where a full DNA profile consists of 16 markers, Item BZ had eight surviving markers.

Because the DNA profile was partial there is a chance Item BZ does not belong to Halbach, however that chance is slim. According to Forensic Scientist Sherry Culhane the chance is at least one in one billion.

Forensic anthropologist Leslie Eisenberg observed that the bone was charred, but "perhaps not really burned" and "certainly not to the degree of the other [bones]".

## Description

Bone material that was described as "unquestionably human" by forensic anthropologist Leslie Eisenberg. The colour of the bone is more consistent with bone from a non-burn case. Eisenberg believes the tissue surrounding the bone must've given the bone some sort of protection from the fire.

## Forensic examination

*see also: burned remains*
The charred bone sample was taken into the forensic lab on 11 November 2005. Forensic scientist Sherry Culhane took custody of the item and designated it Item BZ. Charred tissue was observed and a portion of it was sampled for DNA.

The bone and tissue had been subjected to intense heat and the DNA in the tissue had been damaged, making it impossible to develop a full DNA profile from it. However, Culhane was able to obtain a partial DNA profile. The partial DNA profile had seven surviving markers (where a full DNA profile has 15 markers). The partial DNA profile was compared to Teresa Halbach's DNA profile and all seven surviving markers were a match.

According to Culhane there is a chance of one in one billion in the Caucasian population that Item BZ isn't Halbach's.

## At trial and appeals

### 2007 Steven Avery trial

Item BZ was used at Steven Avery's trial to establish that the bones recovered from Steven Avery's burn pit were Teresa Halbach's. To the prosecution it is important in a murder trial to show that the victim is indeed deceased. Due to a laboratory policy based upon world population Culhane could not undoubtedly attribute the bones to Teresa Halbach, but she was able to tell how rare or common this partial profile was. One person in one billion in the Caucasian population, one person in two billion in the African-American population and Southeastern Hispanic population, and one person in three billion in the Southwestern Hispanic population.

### 2007 Brendan Dassey trial

Item BZ was used at Brendan's trial in a similar way.

### 2016 - 2021 Kathleen Zellner investigation

Item BZ was mentioned in just one file by Kathleen Zellner, which was her December 2018 motion for new scientific testing on the quarry bones.

## Sources

1. ↑ *Avery Trial Transcripts*, day 10 - testimony of Sherry Culhane, page 157
2. ↑ 2.0 2.1 *Avery Trial Transcripts*, day 10 - testimony of Sherry Culhane, page 162
3. ↑ *Avery Trial Transcripts*, day 13 - testimony of Leslie Eisenberg, page 134
4. ↑ *Avery Trial Transcripts*, day 13 - testimony of Leslie Eisenberg, page 135
5. ↑ 5.0 5.1 *Avery Trial Transcripts*, day 10 - testimony of Sherry Culhane, page 158
6. ↑ *Avery Trial Transcripts*, day 10 - testimony of Sherry Culhane, page 159
7. ↑ *Avery Trial Transcripts*, day 10 - testimony of Sherry Culhane, page 161