The jurors walked away from the box on Thursday with ample knowledge of how DNA is collected from a crime scene and the methodology crime labs use not only to collect, but also to process the evidence.
The prosecutor started the day with five witnesses remaining to call to the stand, and ended the day with one remaining.
Everyone Prosecutor D.J. Hilson called to the stand worked for the state police forensics division. The first witness, Katherine Meredith, told the jury that no DNA was found on the fire casings found at the site of Bletsch's murder. Meredith's testimony brought up a concern of a policy change in the way evidence was processed between the time Bletsch was murdered (2014) and the time of the investigation (2016).
The defense also inquired if household cleaning items are capable of wiping out DNA, or if household cleaners can be used to clean the crime lab. Meredith said yes.
The second witness, Sarah Rambadt of the state police forensic lab in Grand Rapids, provided breakdowns of reports she authored during the Bletsch investigation.
David Hayhurst, a scientist with the state police forensic lab's Biology and DNA Unit in Grand Rapids, took the better half of the day with his testimony. The key takeaways of his testimony included the following:
— Willis' DNA found on red ball gag.
— Willis' DNA found on leather restraint.
— Willis' DNA found on muzzle, slider of gun.
— Bletsch, MJN and Jessica Heeringa's DNA not found on either pair of panties found in Willis' possession.
— Bletsch, MJN and Heeringa's DNA not found on ball gag.
— Multiple items within Willis' minivan revealed the DNA of several different people, but the main contributor was Willis, and the other DNA profiles were not complete enough to be identified.
— DNA can be preserved over time.
— DNA profiles used throughout points of this investigation included: Jeffrey Willis, MJN, Rebekah Bletsch, Jessica Heeringa, Michelle Schnotala and Kevin Bluhm.
The two pairs of underwear found in Willis' home belonged to Schnotala, a former co-worker of Willis. She said during her testimony Wednesday that the underwear must have been stolen and she often leaves her home unlocked.
Jeff Crump, the final witness of the day, works for the state police Forensic and Firearms Unit in Grand Rapids. He served as an expert in firearm examination.
Crump said the serial number had been scratched off the weapon found in Willis' van, but Crump was able to recover the serial number and identify the gun. Crump said the bullet fragments found in Rebekah Bletsch's head were fired from this gun.