Crime lab did not test equipment after unusual readings
A piece of equipment used to process Dakota County drug evidence was improperly maintained, and even when it showed signs that results could be wrong, a lab worker did nothing about it, an analyst at the St. Paul police department drug lab testified Friday.
Roberta DeCrans, the only witness to testify during the evidentiary hearing this week, said there could have been contamination to drug evidence that occurred with the gas chromatograph-mass spectrometer at the lab during testing.
The GCMS is a highly-sensitive instrument that identifies chemicals, in part, by how quickly they travel through a polymer tube. It also identifies them based on mass after a process turns them into particles of positively charged ions.
Analysts are able to set the range of ion mass for the instrument to detect.
When one of those tests showed an abnormal range, but DeCrans said she continued to test samples with the machine. She said she did not document if she alerted maintenance workers about the issue, which she admitted could indicate the tubes (or columns) chemicals go through may need to be replaced.
DeCrans also said she does not follow a single set of procedures on every scientific test she performs. According to her testimony, sometimes she ran follow-up tests when initial results showed no drugs present, and other times she did run the samples again.
Public defender Lauri Traub challenged Dakota County Attorney Phil Prokopowicz’ repeated use of the term “standard operating procedures” when referring to the work DeCrans said she typically performed when testing evidence used in Dakota County drug cases.
Traub challenged the term because accepted scientific standards indicate “standard operating procedures” are written, verified, tested and consistently followed.
Procedures employed at the St. Paul crime lab did not meet that standard, as previous testimony revealed.
Once the crime lab’s operations became publicized after July testimony in the hearing, the drug lab testing was shut down, the head of the lab replaced and the law enforcement entities that used the lab for testing drug evidence, including Dakota County, stopped sending samples there for testing.
The drug evidence has been undergoing retesting by the Bureau of Criminal Apprehension’s drug lab, but the defense is also claiming retesting cannot rectify damage done by the St. Paul crime lab.
DeCrans said Traub’s questioning to determine the proper scientific term for the work she performed on drug cases was “getting a little nit-picky on terminology.”
“Science is nit-picky,” and “requires precision,” Traub replied.
Previous testimony revealed the unaccredited St. Paul crime lab’s operations lacked standard operating procedures performed by under-trained workforce that employed lax standards, improper testing procedures, failures to maintain equipment and an under-trained workforce.
The Frye-Mack hearing has included a cross-section of Dakota County drug cases where evidence was tested by the St. Paul crime lab; its purpose is to explore whether scientific evidence can be presented against an accused defendant in trial.
Traub and Christine Funk of the State’s Public Defender’s office have argued the evidence is contaminated and should be thrown out.
Some of the seven cases originally included in the hearing are expected to be removed after the Bureau of Criminal Apprehension crime lab concluded drug evidence was determined to be too insufficient to retest.
Those cases will continue through the legal process independent of the hearing, and will allow evidence like drug paraphernalia, Prokopowicz said.
He noted that tests of samples on the remaining cases involved in the Frye-Mach hearing, which , have been given a high priority by the BCA to conclude testing.
The hearing will continue Sept. 6.