BRENTWOOD, N.H. — A Maine woman who pleaded guilty to helping her brother kill his ex-wife in New Hampshire will serve at least nine years in prison

Rockingham County Superior Court officials confirm that Michele Corson of Skowhegan, Maine, was sentenced to 9-30 years in prison Wednesday in connection with the March 2013 killing of Amanda “Amy” Warf.

Prosecutors said Warf’s ex-husband – Aaron Desjardins of Epping, New Hampshire – ambushed her in her workplace parking lot and forced her to drive to a vacant concrete plant in Exeter, where he slit her throat, poured gasoline on her and set her ablaze. Desjardins, 39, pleaded guilty to first-degree murder and conspiracy and was sentenced in March to life in prison without possibility of parole.

Prosecutors say his plan to kill her dated back to 2011, when she left him. Officials say he was upset over custody of their young son, William.

Corson, 44, pleaded guilty last year to conspiracy charges and said she brought a gun from her father’s house in Maine to give to her brother. Prosecutors say he used the gun to threaten Warf to get into her car and drive to the concrete plant.

His current wife, Sarah Desjardins of Epping, was sentenced in August to 15-30 years in prison, after pleading guilty to conspiracy to commit murder and conspiracy to hindering apprehension. She was charged with helping to plan Warf’s death, providing advice to her husband on how to avoid detection, giving him a false alibi, and/or sending a text message to Corson to bring the gun.