Sin Seer by Andrew Shaw aka ??? (Nightstand Books, 1966)
This one wasn’t penned by Lawrence Block and there are no clues who wrote this, of the many other Andrew Shaws, such as William Coons or David Case. It does have some crime elements and the multi-character narrative that Block often used in his Shaw novels.
The setting is Neuvo Lardo, in Mexico at the Texas border; in 1966 it was a haven for Americans to gamble,party, and have sex with a variety of prostitutes; today, of course, it is blood-spattered from the drug cartels. The novel focuses on a number of Americans who find themselves down south, and eventually their lives cross paths — much like Crossroads of Lust, so this might be Coons imitating Block as he has done in other Shaws.
Sharon is a lost soul who works the bars down south, and seems to have the gift of precognition, hence the title. Eddie and Lee are a couple of criminals on the run, Lee a sadistic psycho serial killer. Kitkat Kelly is a butch lesbian who performs in dyke shows for people to watch, and seduces Mexican girls on the side — she is a female Humbert Humbert, and in one strange chapter she works on a slow seduction of a preteen Mexican girl who seems virgina, although she notes in Neuvo Ladro, any girl keeping her virginity past age seven is rare, and many preteen girls make themselves available to pedophile gringos.
A good read–many of the post-1965 Shaws aren’t–but confusing at times with too many characters. Worth looking at if you come across a copy.