FARMINGTON, N.M.—Farmington police have arrested a man in an alleged plot to retaliate for the killing of a man repeatedly shot while in a parked car with his family at a mall.

Police say the alleged plot was a reaction to the April 27 killing of Johnny Vialpondo. Police previously stepped up patrols in neighborhoods amid fears of a gang war.

According to police, 24-year-old Justin Dedios of Farmington was arrested on suspicion of conspiracy to commit murder.

Police did not immediately return a call for further information about the alleged plot and Dedios, including whether he has an attorney.

A judge Wednesday ordered that alleged getaway driver 28-year-old Luis Ramirez, one of two Kirtland brothers charged in the killing, stand trial on murder and other charges.