Ms Downe: Yes

AJM41 and AJM46 samples underwent a number of DNA extraction and amplification processes performed by Ms Downe in 2003. 

In 2004, when the exhibits were transported to a NZ lab for Y chromosome testing, a blank relating to runs the exhibits were on was found to have been contaminated with female DNA that was not Ciara's. 

It's not yet clear when and in what lab the contamination occurred, and testing to determine whose DNA it was was not undertaken at the time, as the NZ lab was only interested in trying to find male DNA. 

Mr Yovich is now going through the different blanks associated with the Pathwest testing runs for AJM41 and AJM46, and where each blank was stored in the freezer afterwards. 

Mr Yovich: If DNA is detected on a blank, what is the consequence? 

Ms Downe: If what might be part of or a DNA profile [is detected], then we look at where that DNA may have come from, because it should have no DNA in it at all.

Mr Yovich: If it has DNA in it, that may mean that the parent sample, the AJM nail exhibits, any DNA finding in relation to those may be invalidated? 

Ms Downe: We would look at that result and try to determine where that DNA came from and looking back at who handled the exhibit. 

Ms Downe said if a blank was found to be contaminated during a run, it should have been noted on documentation, and investigated. 

She said she does not recall a blank in the DNA testing process returning a positive for DNA. 

The state does not rely on the testing or results from AJM41 and AJM46 (Ciara's left and right index fingernails), which returned only Ciara's DNA. 

Mr Yovich has completed his cross-examination. 

During re-examination, Ms Downe has explained that the contamination of a blank does not always mean the entire run is invalid as it could mean the staff member handling the blank could have contaminated only the blank. 

She also explained Pathwest had a staff DNA database to cross-check if contamination was detected.