Moroni Traveler Jr. (1988-95 Book Series)
The Salt Lake City P.I. created by Robert Irvine carries a lot of baggage. For one thing, he's a lapsed Mormon saddled with the name of the angel who gave Joseph Smith the golden plates. For another, the cases he handles — about a missing missionary (in The Angel's Share) or the wayward daughter of a member of the Council of Seventy (in Baptism for the Dead, or a woman housing a polygamous offshoot sect (in Gone to Glory) — often lead him to suppressed scandals within the church. A former soldier and football player, Moroni Jr. is in partnership with his detective dad, who gets into more mysteries than he can solve and who may not be our hero's biological father.
A mystery is why books aimed at a Mormon readership would contain so many Mormon villains. (Probably because in crime fiction, the bad guy must always be a figure of power, and in Utah, the church is where the power is.) Anyway, Irvine's gnarly plots and unfettered style must have appealed to a lot of readers, Mormon or otherwise; the author produced a new volume for Dodd, Mead every year for eight years. The series may have ended with Irvine's death, though there's no hint on the Internet. How obscure does a writer have to be to not have a Wikipedia entry?