The state Supreme Court has overturned the murder and arson convictions of a southern Missouri man who was charged in the death of his grandmother-in-law.

The high court ruled Tuesday that an Oregon County judge violated state law when he called back an alternate juror, who had already been discharged, to take over for another juror who developed health problems after five hours of deliberations.

Shortly after the juror switch, the panel found Michael Amick guilty of second-degree murder and second-degree arson in the December 2008 death of Leona Maxine Vaughan at her home in the Arkansas border town of Myrtle. He was sentenced to life in prison for murder and seven concurrent years for arson.

The Supreme Court ordered the case sent back to the trial court.