Judge Sally Duncan dismissed first-degree murder charges against Jeffrey Martinson in the 2004 death of his 5-year-old son, Josh, and ordered the father be released Sunday, The Arizona Republic in Phoenix reported Tuesday.
Duncan dismissed the charges "with prejudice," meaning Martinson cannot be tried again on the same charges.
In a 28-page ruling, Duncan detailed what she called the prosecution's "win-by-any-means strategy."
Duncan said Deputy Maricopa County Attorney Frankie Grimsman charged Martinson with felony murder, then tried him as if he were charged with premeditated murder.
Martinson's conviction was thrown out because of improper testimony from a medical examiner and juror misconduct. Grimsman then tried to re-indict Martinson for premeditated murder, Duncan said, and made repeated attempts to get Duncan and defense attorneys thrown off the case "specifically to avoid the risk of acquittal during any trial," Duncan wrote.
"When viewing the totality of circumstances, the court finds that during trial the prosecutors engaged in a pattern and practice of misconduct designed to secure a conviction without regard to the likelihood of reversal," she wrote.
Martinson has been in jail nine years as he awaited a final verdict.
Prosecutors can appeal Duncan's ruling.
County Attorney Bill Montgomery said he would review the judge's allegations and "the conduct of defense counsel and that of the judge for appropriate action."