Georgia's highest court on Monday reversed the murder conviction of a man imprisoned for killing a father who had just dropped off his son at preschool, renewing a criminal case that prosecutors said stemmed from a deadly love-triangle.

The Georgia Supreme Court rendered the 6-1 decision in the case of Hemy Neuman, who was sentenced to life in prison without chance of parole for the November 2010 killing of Russell "Rusty" Sneiderman. A jury in March 2012 found Neuman guilty but mentally ill of malice murder in Sneiderman's death.

Neuman, who worked with Sneiderman's wife Andrea, donned a fake beard as a disguise and opened fire moments after Russell Sneiderman dropped off his 3-year-old son at Dunwoody Prep daycare, prosecutors said.

At Neuman's trial, both the prosecution and the defense contended Neuman and Sneiderman's wife were having an affair. Andrea Sneiderman has repeatedly denied it.

The DeKalb County District Attorney's office is prepared to retry Neuman, office spokesman Erik Burton said. Neuman will remain in custody because a request for bond was denied prior to his trial, Burton said, adding that Neuman could ask a judge to reconsider.

In its opinion, the Supreme Court said the trial judge erred in allowing notes and records of two mental health experts who examined Neuman before trial.

"Because the trial court erred in admitting evidence, which was protected by the attorney-client privilege, we now reverse," Justice Carol Hunstein wrote.

The attorney-client privilege is "the oldest of the privileges for confidential communications known to the common law," the opinion states.

Prosecutors suggested during Neuman's trial that Andrea Sneiderman was a co-conspirator, but they said Neuman was ultimately driven to kill Rusty Sneiderman because Neuman wanted Sneiderman's wife and his money. Neuman's defense attorneys said their client was mentally ill and that Andrea Sneiderman manipulated him into killing her husband.

Andrea Sneiderman was convicted of lying during the investigation of her husband's killing. She was released from prison in June 2014.

Justice Harold Melton focused his dissent on a form that Neuman signed in jail before meeting with both mental health experts. The form stated their examination of him was "not confidential" and that anything discussed may be included in reports or disclosed in court, according to Melton's dissent.

"The attorney-client privilege protects communications between the client and the attorney that are intended to be confidential; the protection does not extend to communications which are not of a confidential nature," Melton wrote in his dissent.

According to court documents, the experts each met separately with Neuman once and later held a meeting together with Neuman at the jail where he was being held. The majority justices said the form was only used at the jail meeting.

The earlier meetings and communications between Neuman's attorneys and the experts were intended to be confidential "as part of the attorneys' assessment of the viability of an insanity defense," the opinion states.

Paul Milich, a professor at Georgia State University's College of Law, said the high court's decision will prevent prosecutors from using the experts' conclusions again. He also expects prosecutors to zero in on Neuman's insanity defense and avoid problems that cropped up during the first trial, including a "difficult witness" in Andrea Sneiderman.

"Whenever you retry a case, you have the advantage of learning from the lessons of the first trial," Milich said.