Twice Buried - Steven Havill

"Gastner is an incisive investigator whose two most valuable qualities are compassion and insomnia. Unlike other fictional detectives who approach murder as a personal affront, Gastner sees himself as the victims' advocate, striving to even the scales of justice for those no longer able to do it themselves." --Booklist

Bill Gastner, Undersheriff of Posadas County, knows ancient Anna Hocking didn't fall down her fruit cellar stairs by accident. He's also sure that elderly Reuben Fuentes knows nothing about the bodies scattered on his dusty, southern New Mexico ranch. No spring chicken himself, Bill summons his former deputy, Reuben's niece, from Mexico to help clear the old man of suspicion. Eventually this generation-spanning law enforcement team finds a thread tying all the crimes together - a killer with no conscience.