IN DETROIT, a "blind pig" is an illegal after-hours tavern that opens after other bars close at 2 a.m. it's a place where late-shift factory workers can get booze and prostitutes at four in the morning and where the underworld can trade in drugs, guns, and schemes. The Blind Pig (Random House, $7.95) is Jon A. Jackson's second novel with Detective Sgt. Mulheisen, a tenacious if slightly weary big city cop who has seen it all. This one is a top-notch thriller that explodes with the violence of today's big cities -- gun runners, mob-connected truckers, hit men, and Cuban conspirators. It's a sleazy, dirty scene, but Jackson manages to find human survivors like Mulheisen, and a female undercover agent, and also Benny, the ex-head waiter who runs a hightoned blind pig and would like to add a good restaurant to his establishment.

It's another one of those police-blotter stories from Elizabeth Linington (she's also Dell Shannon) with No Villain Need Be (Doubleday Crime Club, $7.95). It's been a popular and successful formula, and Linington doesn't chance anything new or different as she juggles several assignments for her husband-wife team of Sgt. Ivor Maddox and Detective Sue Maddox of the Los Angeles Police Department. Linington handles her plots and subplots with the usual expertise, but lately she has been indulging in hectoring discourses against "soft" judges, street punks, and the urban "jungle." The stories make the point more effectively.