As the cover lets you know, "W. B. Murphy" is Warren Murphy, co-author of The Destroyer series. I guess that one didn't occupy all his time, so he came up with another one, and it's a winner. I don't have all the books in hand, so I don't know for sure how many there were. Four, maybe. Too bad, since they're all great reading. The series should have lasted longer.
The cover also lets you know that the book's about a black-and-white detective team. The black member is "Tough" Jackson. He "cared about results, he never protected a narcotics peddler, he was never charged with brutality (officially), he considered himself a good cop."
His partner is Ed Razoni, "who shared his bachelor apartment with a maiden cat, whose virginity he protected like his private phone number."
Did you ever see a movie called Lethal Weapon? You might notice a strong resemblance to the Jackson/Razoni series. Except the books are a lot better. Grittier, tough, and just plain fun to read. Grab 'em if you can find 'em.