PORTLAND — A Biddeford man serving two life sentences for gunning down two brothers outside his home in a late-night confrontation is appealing his conviction and sentence.

The Maine Supreme Judicial Court heard oral arguments today on Rory Holland’s appeal of his conviction of two counts of murder and the two life sentences he received.

Holland maintained he acted in self-defense when he fatally shot 19-year-old Gage Green and his 21-year-old brother, Derek, at about 1 a.m. on June 30, 2009.

Holland is making seven arguments, including some that relate to the evidence allowed at his trial. During today’s proceeding, one focus was on whether evidence about the victims’ background and gang affiliation should have been allowed.

Amanda Doherty argued on Holland’s behalf Maine should, as 45 other states do, follow a federal rule that would have allowed information about the victims’ aggressive nature.

Assistant Attorney General Donald Macomber argued that Holland’s lawyers were trying to besmirch the character of the victims. He noted that information about Holland, including his status as a felon and a conviction for attempted murder, had been excluded from the trial.