A judge now has 90 days to decide whether problems with evidence handling compromised results.
Although Dakota County prosecutors voluntarily agreed not to use drug test results from the St. Paul police crime lab, it was not a concession that the lab's work was scientifically unreliable, said a Dakota County official.
Chief Deputy County Attorney Phil Prokopowicz filed his memorandum with the court on Tuesday, signaling the end of court arguments in a drawn-out hearing about the crime lab's work and reliability. The hearing started in July and continued into October over eight days of testimony.
Public defenders Lauri Traub and Christine Funk are seeking to stop the admission of Minnesota Bureau of Criminal Apprehension (BCA) test results in four Dakota County drug cases, citing possible contamination at the police lab. The evidence in those cases was first handled at the police lab, where Funk and Traub believe poorly maintained instruments and varying cleaning practices could have corrupted the samples.
Testimony revealed widespread problems with the lab's work, including a lack of documentation in testing procedures, no written standard operating procedures for several practices and no vetting of questionable test results.
Police Chief Thomas Smith suspended the lab's testing right away, and Dakota County prosecutors voluntarily decided in August that they would not use the lab's results in any pending cases. Traub and Funk seized on the latter development as ammunition in their memorandum.
Prokopowicz's response argued that defense attorneys mischaracterized the state's stance on the lab's reliability. He also said that the samples tested by the BCA had only been handled by the police lab.
"At the time the State did not, nor does it now, concede that the chemical analysis performed by the [police lab] is scientifically unreliable," Prokopowicz wrote in his rebuttal to their argument. "It remains the position of the State, as demonstrated by subsequent testing performed by the BCA, that the results of chemical analysis by the [police lab]" are reliable.
BCA tests of the contested cases have supported St. Paul's initial results. In two unrelated cases, BCA tests contradicted St. Paul's findings. In one case, the BCA found no narcotics where St. Paul had found methamphetamine. In the other, the BCA found a controlled substance where St. Paul had not.
Prokopowicz wrote that the police lab was "merely a 'link'" in the chain of custody.
In his first memorandum filed in November, Prokopowicz noted that the BCA and police lab shared many similar practices when it came to evidence handling and cleaning workplace surfaces. He argued that those similarities would lead a jury to reject the possibility of contamination at the police lab.
The BCA lab is accredited, and must meet numerous criteria and submit to regular testing of staff knowledge and skill level. The police lab is not accredited and operates with no outside oversight.
Judge Kathryn Davis Messerich has 90 days to issue her decision.
The city hired consultants to review and revamp the crime lab's practices, and the City Council approved a budget this month that includes $1 million for the lab.
Chao Xiong 612-270-4708 Twitter: @ChaoStrib