State public defenders have had little success getting drug-related convictions re-examined following a court case that exposed widespread failings at the former St. Paul crime lab.

This summer, they identified about 1,700 drug cases in Ramsey, Dakota and Washington counties that could qualify for "post-conviction relief" because the evidence originally presented to the crime lab could have been mishandled or misinterpreted. But so far, attorneys in the already strained public defender's office have filed for relief — anything from a shortened sentence to a dismissal of charges — in 17 cases where defendants were convicted with evidence that relied on the police lab.

Prosecutors have largely taken a hard-line stance on the challenges after a judge ruled earlier this year that evidence that had been retested could be used in court. Since then, many requests haven't made it past the filing of copious paperwork; judges denied evidentiary hearings where arguments could be hashed out in open court and requests to withdraw guilty pleas were denied. The decisions, made in chambers based on court transcripts and written arguments, are well within a judge's purview — but frustrate the public defender's office.

"[Prosecutors] want to hold onto the convictions," said Jenny Chaplinski, an attorney in the appellate unit who is spearheading the challenges. "That's their job; I get that.

"I thought there would be a lot more open communication between the public defender's office, or myself, and the prosecutors' offices, and that hasn't been the case."

Only two defendants have met with some degree of success — their convictions in Washington County were reduced from felonies to misdemeanors and they were released early from probation after prosecutors and defense attorneys negotiated.

"In this case, the two lawyers talked and saved everybody time," said Fred Fink, criminal division chief for the Washington County attorney's office. "I thought it was a reasonable way to handle things. The state still walked away with a … conviction."

Chaplinski isn't optimistic about the status of the remaining cases. Six cases in Ramsey County have been denied post-conviction relief, six are pending and one was dismissed by the defendant. Two are pending in Dakota County.

Both sides face a delicate balance as they continue to navigate fallout from a hearing last year that showed major scientific flaws with how the St. Paul police lab tested suspected drugs. Everyone agrees that the lab had problems even as people were convicted with evidence it produced, or pleaded guilty before evidence could be sent there for testing.

But prosecutors and defense attorneys have clashed about how much review, if any, older cases should receive in light of the revelations. For Chaplinski and others at the public defender's office, the implications merit thorough vetting — and a hearing in court — for anyone who steps forward.

Meanwhile, county attorneys note that when the Minnesota Bureau of Criminal Apprehension (BCA) retested 197 drug cases first tested by the police lab, conflicting results were found in only three cases. In one instance, the BCA found no illicit drugs where police had, and in two cases, the BCA found suspected drugs where police had not.

Two cases that sought post-conviction relief in Ramsey County were recently retested by a lab in California. The results supported the police lab's findings of cocaine and ecstasy.

"If we think we can prove [a case] again, we would have little incentive to back off," said Assistant Ramsey County Attorney Kaarin Long with the criminal appellate unit.

Long is handling the 13 post-conviction cases in Ramsey County. Post-conviction relief could include anything from a reduced sentence to dismissal of the conviction. Prosecutors say they're cooperating with the process, but aren't backing down from cases where a conviction should stand.

"Our position has been when you plead guilty you take an oath and you swear that you possessed cocaine or meth or whatever, and we're able to rely on that," Long said. "In guilty pleas, the state did not prove its case beyond a reasonable doubt because the defendant agreed that we didn't have to … so those guilty pleas are not being withdrawn because of that."

The issue started in Dakota County District Court in July 2012 when a number of defendants challenged the scientific credibility of the police lab's results. They then asked District Judge Kathryn Davis Messerich to throw out a second batch of results from the BCA because the evidence was first handled at the police lab, where public defenders said questionable methods could have tainted evidence.

Messerich issued a decision in June 2013 ruling that the second tests could be admitted in court. The ramifications of that hearing continue to reverberate even though St. Paul police stopped all drug testing in 2012 and implemented major changes to bring the lab, now called the forensic services unit, up to standards.

Prosecutors say time is ticking for people who want to challenge their convictions. Minnesota law permits defendants to file for post-conviction relief within two years of their sentencing date. The statute allows for rare exceptions, but Chaplinski argues that defendants should be given two years' time from when the problems were exposed.

"Our original plan was to contact people, but so many people contacted us that we wound up with very large caseloads without having to reach out to those 1,700 people," Chaplinski said.

Chaplinski's office plans to keep filing more challenges while keeping an eye on a few of the rejected efforts, which have gone to the Minnesota Court of Appeals.

Dakota County Attorney James Backstrom said his office voluntarily had evidence retested in two cases where defendants were convicted at trial, but is taking a hard stance on convictions from guilty pleas. The second tests confirmed police tests.

"We worked hard to resolve these issues as quickly as we can, and I feel we've done a good job of that," Backstrom said.

Chao Xiong • 612-270-4708 Twitter: @ChaoStrib