Scarred Souls. The Deiform Fellowship, #4

When a nun walks into a police station and confesses to murder, the Grayhurst police arrest her for the killing spree that has shocked the city. But Roberta believes Sister Catherine is innocent and sends Jillian and Sam to investigate. Sister Catherine gives them the silent treatment, and all the evidence points to her. Jillian and Sam reluctantly conclude that Roberta must be wrong. Then Jillian receives a phone call that forces them to reconsider their view of the case.
Determined to find out why a nun would confess to murders she didn't commit, Jillian and Sam chase down the new lead with renewed enthusiasm. If Sister Catherine is innocent and they don't uncover the truth, the real killer will get away with murder. The Deiform Fellowship series is a mystery series that can also be considered urban fantasy. Deiforms are sleuths who possess supernatural powers bestowed by God-according to some.
Jillian is an atheist. She believes that her powers come from within herself. Because she works with Sam, who is a Christian, discussions about God naturally arise, but the books aren't religious fiction. Each book in the series can be read standalone, but since every book reveals information about the Fellowship and its members, the books are best read in order.