Justice Jane Dixon on Friday discharged 12 jurors after they were unable to reach a unanimous verdict.
Jurors had notified the court on Thursday they didn’t think they could reach an agreed verdict, but she urged them to persist.
On Friday a single juror wrote a note to the judge, prompting her to discharge the whole group.
She noted the high level of distress they had experienced in trying to reach a unanimous verdict and excused them from being on a jury again.
Justice Dixon urged them to part in peace and goodwill.
A retrial will be scheduled at a later date.
Prosecutors had alleged Baker killed Gatt sometime between April 19, 2017, and his 50th birthday four days later.
Her cause of death could not be determined because of the length of time before her body was found.
She was partially naked, wrapped in power cords and covered with a hair dryer, a lamp and other household items.
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A grey stuffed bear was positioned toward her head.
Prosecutor John Dickie argued her murder, a month before her 40th birthday, was motivated by Baker’s jealousy.
Gatt also had an on-off relationship with a woman named Leona Rei-Paku, who Baker’s lawyer John Saunders argued was an alternative suspect.
Both relationships were violent, the court was told.
“Andrew Baker did not murder Sarah Gatt. He is not responsible for her death,” he said.
Justice Dixon earlier had to discharge a single juror in the case after he admitted trying to flirt with a journalist outside court.
Jurors are instructed not to speak to anyone involved or connected with a case.
If you or someone you know is impacted by sexual assault, domestic or family violence, call 1800RESPECT on 1800 737 732 or visit 1800RESPECT.org.au.
In an emergency, call 000.
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