Debra Milke has spent 22 years on death row for the murder of her 4-year-old son -- and she might go free.

On Thursday the 49-year-old’s convictions of murder, conspiracy to commit murder, child abuse and kidnapping were thrown out by a federal appeals court judge, CNN reports. In his explanation behind his decision, Chief Judge Alex Kozinski cited that the case was tainted by a Phoenix police detective who had a history of lying on the stand.

The person Kozinski cited is former detective Armando Saldate Jr., who had a history of lying under oath and violating suspects' Miranda rights during interrogations, CBS reports. He testified in Milke’s case, saying she confessed to plotting her son’s murder.

This information was not shared during the trial which, the three-judge panel argued, denied Milke the right to a fair trial outlined in the Constitution, according to the news outlet.

Now, Arizona authorities must turn over all of the detective’s personnel records as ordered by the lower court. Once the material is produced, prosecutors will have 30 days to decide whether to retry Milke or she will be released from prison, according to the AP.

During the trial, prosecutors said Milke dressed her son Christopher in his favorite outfit and told him he was going to see Santa Claus at the mall, CBS reports. Instead, he was taken to the desert where Milke’s boyfriend and another man shot him three times in the back of the head. Prosecutors said that she had plotted to kill her son to collect a $50,000 life insurance policy, according to the news outlet.

Milke would have been the first woman executed in Arizona since Eva Dugan in the 1930s, according to Fox 10 News.

Related fact: Eva Dugan, who was convicted of murdering a chicken rancher, was the first and last woman to be hanged to death in Arizona. When she dropped to her death, the rope snapped and her head was severed from her body. According to witnesses, her decapitated head rolled across the platform to spectators feet. After the incident, the practice was banned.