Next witness: Matthew Quartaro, Forensic DNA consultant. He reviews work from laboratories around the country and helps attorney teams prepare their best case. He has testified upwards of 90 times in criminal courts, mostly for prosecutors.
Defense asks about DNA collection, emphasizing that DNA cannot say when or how it got to its location, only that it exists.Quartaro says he reviewed all the documents for this case, which was vast. Looked at DNA profiles. Can't recall seeing swab samples from a Jeep.
Quartaro says he did not recognize any serious flaws in the testing procedures for this case. Quartaro reviewed the results of the testing on the Sig Sauer 9mm pistol. Reminds the jury there was one other DNA profile that was unknown on the pistol in addition to trace DNA left behind by Strickland and Armstrong. Quartaro reminds the jury that the swab was taken on the trigger, trigger guard, safety, magazine, etc. and that all of those samples were taken using one swab. Quartaro confirms that one swab will not be able to differentiate which of those locations the DNA was pulled from.
"There is additional genetic DNA there that is not consistent with any of the samples that we have," Quartaro says about the unknown third DNA profile found on the gun.The samples that they have and were asked to compare to were Armstrong, Strickland, Wilson and Cash.
There was a Y chromosome present on the bicycle handlebars, indicating male DNA, but there was not enough of it to create a full profile, Quartaro says.On the bike seat, there was also DNA of three individuals, including one unknown. The other two were Armstrong and Wilson.
About the unknown samples: Can't say if it's one/the same person or multiple unknown people. All Quartaro knows is that it doesn't match any of the four known profiles that were analyzed.
Quartaro discussing transfer DNA and how someone doesn't have to necessarily touch something in order for their DNA to be on it. Someone else can act as the intermediary. Blood, saliva, semen and skin are the main sources of DNA, Quartaro says.
Quartaro says it’s impossible to say if Armstrong's DNA found on the bicycle is trace or transfer DNA. Defense asking if motorcycle could be a good source for DNA. Quartaro agrees. Defense offering hypothetic situations for Quartaro to explain to jury how transfer DNA works.
Witness passed.
State redirect:
Asks about possibility versus probability. State asks if Quartaro plays the lottery? "There's a possibility you can win the lottery, but not a very good probability," State declares. Quartaro agrees. Now turning to the bicycle: Possible Armstrong's DNA is on it? Yes. Probable her DNA is on it? Also yes.
Quartaro says that you might shed more DNA if you were nervous or your hands were sweaty. Causes State to now pose a hypothetical: If you were using a weapon to shoot someone, might you be nervous and thus shed more DNA? Quartaro agrees.
Quartaro says he is not here today to tell us how Armstrong's DNA ended up on the bike, only that it is there. No further questions from the state.
Defense redirect.
Quartaro confirms blood, semen, saliva and bodily fluids are rich sources of DNA with higher concentrations. And when discussing helmet DNA (which was not tested but Mo Wilson wore), it could have sweat and moisture within it. The defense is essentially suggesting that Armstrong's sweat DNA from inside the helmet could have been transferred to Mo Wilson's handlebars by Mo Wilson.
No further questions. Witness dismissed.
We are taking a 10 minute break.
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