The Minnesota Supreme Court on Wednesday upheld the murder conviction of a Pope County woman in the case of 4-year-old Eric Dean, whose death led to widespread child protection reforms.

Teachers, caregivers and family members reported Eric for abuse at least 15 times before he was murdered by his stepmother, Amanda Peltier, in February 2013. A jury convicted Peltier of first-degree murder in May 2014 after hearing evidence that she repeatedly bit and beat Eric, and threw him across a room, causing a fatal injury.

The judge in the case sentenced Peltier to life in prison, with a possibility of release in 30 years.

Gov. Mark Dayton demanded an overhaul of the child protection system after the Star Tribune in August 2014 reported on Pope County’s repeated failures to safeguard Eric. The Legislature passed numerous reforms and wrote into law that the “health and safety of a child must be of paramount concern” when counties respond to abuse reports.

In Peltier’s appeal, the Supreme Court agreed with her argument that the prosecuting attorney, Robert Plesha, made several improper remarks in his closing arguments, such as disparaging Peltier’s defense. Plesha, an assistant attorney general, implied to the jury that Peltier wanted a trial “in a desperate attempt to ‘roll the dice,’ ” Associate Justice Christopher Dietzen wrote in the opinion.

“These statements were untrue and disparaging, and constituted misconduct,” Dietzen wrote

But the Supreme Court ruled that Plesha’s misconduct did not affect Peltier’s rights.

The evidence “overwhelmingly demonstrates that Peltier engaged in a pattern of malicious punishment of Eric before his death.”

The court dismissed other arguments made by Peltier’s attorneys, including that a key witness for the prosecution, a doctor who had examined the case, prejudiced a jury by saying that Peltier biting Eric was “a particularly vicious form of child abuse.”

Dietzen called the testimony “a close call,” but ultimately found there was no likelihood it affected the verdict.

Peltier, 34, is imprisoned at the Minnesota Correctional Facility in Shakopee.