Silent Order by Melanie Dobson

Rural America - 1928. After the murder of his partner,
Detective Rollin Wells hides away in an Amish home near
Sugarcreek, Ohio, to find out who in the police force is
collaborating with Cleveland’s notorious mob.
While Rollin searches for answers to his partner’s death,
he befriends an elusive young Amish woman named Katie
and her young son. As Rollin learns about Katie’s past,
he’s shocked at the secret Katie is hiding - a secret that has
haunted Rollin for eight years.