PORTLAND — A Maine man convicted of fatally shooting his wife because he thought she was having an affair is appealing his 40-year sentence.

Forty-eight-year-old Brian Nichols of Turner pleaded guilty to murder in 2012 to killing Jane Tetreault in their Turner home in May 2010. Nichols told police that he killed his wife because he suspected her of cheating, but an investigation turned up no evidence of infidelity.

Nichols’ attorney is appearing before the Maine Supreme Judicial Court on Thursday to appeal his 40-year sentence, claiming it’s excessive compared to prior comparable cases.