The Pigeon Wing Murders. Lowan, #11

Meet Lowan, a telepathic alien working as a private detective in the 1930s!When a boy brings Lowan an injured carrier pigeon with a coded message strapped to its leg, this isn't the beginning of a normal case. A pigeon keeper is found murdered, and then the codebook is found in a second dead man's pocket. The decoded message warns of an imminent train robbery, but advanced warning might not be enough to stop it.
The thieves target an expensive racehorse-and they're not concerned with how much it's worth. They want it for a more sinister reason. If Lowan can't solve the case in time, the crime spree won't end until the horse's owner is also dead. S. E. Grosskopf's writing is strongly influenced by the old pulp fiction magazines and Golden Age radio dramas of the 1930s-1950s. If you like fast-paced action and mystery with a dash of urban fantasy and quirkiness, then you'll love these books.
This is the eleventh book in the series. The books follow chronologically. Reading them in order is recommended.