Murder suspect Robert Burton, 40, enters court before closing arguments in his trial at Bangor Judicial Center in this Oct. 4, 2017, file photo.

The Maine Supreme Judicial Court on Tuesday upheld the murder conviction of the man who led authorities on the longest manhunt in state history.

Robert Burton, 41, of Abbot is serving a 55-year sentence at the Maine State Prison in Warren for the slaying of his ex-girlfriend, Stephanie Ginn Gebo, 37, of Parkman after breaking into her home more than three years ago. A jury convicted him of murder in October 2017.

Burton, who turned himself in Aug. 11, 2015, after 68 days on the run, had sought a new trial. His attorney, Jeremy Pratt of Camden, claimed the jury should not have been told about two prior convictions for burglary.

Pratt also argued that potential jurors should have been able to answer “unsure” on some questions on the juror questionnaire form, and his attorneys’ proposed questions should have been included on forms filled out by potential jurors.

Justices, who heard oral arguments on Sept. 12, rejected all of those arguments in its 17-page decision written by Justice Jeffrey Hjelm.

“[T]he court explicitly prohibited the parties from explaining the elements of the crime of burglary before the jury, thus avoiding any overemphasis of the evidence and the risk that the jury would improperly compare the details of the prior convictions to those of the current case,” Hjelm wrote.

The justices found that that Superior Court Justice Robert Mullen properly conducted the questioning of potential jurors and was not obligated to include an option of “unsure” on the juror questionnaire.