Except that Robert B. Parker's Jesse Stone was a MLB-quality shortstop or third-baseman (I forget which) before landing on his shoulder and damaging it. Selleck's no infielder. I could see him more as Robert Parker's Spenser.
I love Robert Parker and John Sandford - and you couldn't find two more different novelists. One is a light-hearted light read. Sandford is serious and much more literary. Where they cross is that both are good at building a character and a surrounding cast, and developing them though a series of books. Characters from the Spenser, Jesse Stone, and Sunny Randall series cross believably from one series to the others.
If you enjoy “smart-alecky detective books” as I call them, I like Robert Crais’ Elvis Cole novels. It has a Hollywood/LA setting with plenty of wise-cracking and a silent sidekick. No Susan though.