David Rosenfelt's K-9 series

All four books in the K-9 series "In David Rosenfelt's newest series - a spinoff of the much beloved Andy Carpenter mysteries - Andy's wife forms an investigative team with a former detective and his German shepard partner. Andy Carpenter's wife, Laurie, was a cop, a good one. Now she helps out on Andy's cases while also raising Ricky, their son. But she's been chafing to jump back into investigating on her own, and when her former partner and his German shepard K-9 partner come to her with a proposal, she's in. From the author of the bestselling Andy Carpenter mysteries comes a spectacular new series with a K-9 main character."