A closely divided Minnesota Supreme Court on Wednesday ordered a new trial for a teen mother convicted of stabbing her newborn to death, saying the interference of a county attorney and other officials not connected with the case undermined her defense.

Nicole Marie Beecroft was found guilty of first-degree murder and sentenced in 2008 to life in prison without parole for stabbing her newborn daughter 135 times and throwing the infant into a trash can outside her house. Beecroft, who was a 17-year-old senior at Tartan High School at the time of the birth, had hidden her pregnancy from others, even her mother, according to court documents.

Her lawyers had argued that Dakota County Attorney James Backstrom and the chief medical examiner in St. Louis County, Dr. Thomas Uncini, discouraged other medical examiners from testifying in Beecroft's defense, hampering defense efforts to argue that the baby was stillborn.

In Wednesday's opinion, Justice Paul H. Anderson wrote that because of "improper conduct of certain state officials, a reversal is warranted in the interests of justice."

The reversal means Beecroft is eligible for a new trial in her high-profile murder case. It also carries the wider importance of making clear to Minnesota prosecutors that they must not interfere with medical examiners who are called by defense attorneys to testify.

One of Beecroft's public defenders, Luke Stellphlug, said he "absolutely and enthusiastically applauds" the Supreme Court decision because medical examiners should be free to testify "based on science and not on who's paying their salary."

Without the "chilling effect" of interference, Stellphlug said, he and defense attorney Christine Funk might have proved that the baby was stillborn, exonerating Beecroft.

"She would have walked out of the courtroom a free woman," he said. "You can't kill a person who's already dead."

Two medical examiners who testified for the prosecution concluded that Beecroft's baby was alive at birth. A defense witness who would have disputed those findings, medical examiner Susan Roe, withdrew after Backstrom wrote in e-mails to Roe's superior in Dakota County that Roe's testimony represented a conflict of interest to the prosecution.

"Dr. Roe reviewed these e-mails, feared for her own professional and financial well-being as a result, and subsequently severed all ties with Beecroft's defense," Anderson wrote for the 4-3 court majority. "Thus, we conclude that Backstrom's conduct constitutes substantial interference."

Attorney apologizes

Backstrom said in a statement Wednesday that he regrets "any adverse impact" on Beecroft's trial and accepts responsibility for his lack of judgment. The Supreme Court decision, he said, shows an "ongoing debate at the time of this trial related to the appropriate role of medical examiners in cases outside of their jurisdictions. This decision has settled this debate."

Uncini, the chief medical examiner in St. Louis County, came under criticism in the court decision for restricting his assistant, Dr. Janice Ophoven, from testifying in criminal trials as a condition of employment.

Ophoven, in a report she wrote to Roe in Dakota County, said she found no evidence that Beecroft's baby was born alive. "The evidence is much more consistent with a stillbirth," she wrote Roe.

The managing attorney for the Minnesota Innocence Project, Julie Jonas, said the Supreme Court decision has far-reaching implications.

"I think what they did was abhorrent," Jonas said of Backstrom and Uncini. "To use their decisions and authority to prevent that person from assisting the defendant, to not take advantage of the best experts in the community, it's just wrong."

Anderson wrote in his opinion that "the potential for harm from the error committed here was great. This case was tried before a district court judge, not a jury, and the court's verdict relied heavily on the forensic pathologists who testified."

'Welcome the opportunity'

Washington County prosecutors said during the trial that Beecroft had considered leaving the baby at a hospital before she gave birth in the early hours of April 10, 2007. Minnesota law permits such abandonment within 72 hours of birth.

Beecroft instead stabbed the girl in the neck, chest and abdomen. Several of the wounds penetrated the baby's vital organs, Judge Mary Hannon said in Washington County District Court before she sentenced Beecroft.

Washington County Attorney Pete Orput, who was elected to his position two years after the trial, said Wednesday that he intends to retry Beecroft.

"I welcome the opportunity to have a fresh look at the case with fresh eyes," Orput said. "I think the evidence is strong enough that it warrants retrial."

Beecroft is imprisoned outside Minnesota. Sarah Russell, a Minnesota Department of Corrections spokeswoman, said she couldn't reveal Beecroft's whereabouts and said out-of-state officials wouldn't permit Beecroft to comment on her case.

Beecroft's mother couldn't be reached Wednesday.

Dissenting opinion

The trial by judge in a first-degree murder case in adult court -- Beecroft waived her right to a jury trial -- was rare, then-Washington County Attorney Doug Johnson said at the time. Johnson retired in 2010.

"An important justification for the independence of medical examiners is the public's interest in having accurate scientific findings available during an inquiry into a sudden, unexpected, or suspicious death," Anderson wrote in the court opinion. "The right of a defendant to present a complete defense is an essential principle of our criminal justice system."

One of the dissenting members of the court, Chief Justice Lorie S. Gildea, wrote that Beecroft shouldn't be entitled to a new trial "because the alleged governmental interference was harmless beyond a reasonable doubt." Even if Roe and Ophoven had testified "and the damaging potential of the evidence fully realized, a reasonable trier of fact would have reached the same verdict," Gildea wrote.

Kevin Giles • 651-925-5037 Twitter: @stribgiles