Pay or play / Howard Michael Gould.

Enhanced descriptions from Syndetics:

Blackmail, sexual harassment, murder . . . and a missing dog: eccentric, eco-obsessed L.A. private eye Charlie Waldo is on the case in this quirky, fast-paced mystery. Paying a harsh self-imposed penance for a terrible misstep on a case, former LAPD superstar detective Charlie Waldo lives a life of punishing minimalism deep within the woods, making a near religion of his commitment to owning no more than One Hundred Things. At least, he's trying to. His PI girlfriend Lorena keeps drawing him back to civilization - even though every time he compromises on his principles, something goes wrong. And unfortunately for Waldo, all roads lead straight back to L.A. When old adversary Don Q strongarms him into investigating the seemingly mundane death of a vagrant, Lorena agrees he can work under her PI license on one condition: he help with a high-maintenance celebrity client, wildly popular courtroom TV star Judge Ida Mudge, whose new mega-deal makes her a perfect target for blackmail. Reopening the coldest of cases, a decades-old fraternity death, Waldo begins to wonder if the judge is, in fact, a murderer - and if he'll stay alive long enough to find out.Pay or Play is the third in the Charlie Waldo series, following Last Looks and Below the Line. Last Looks was turned into a major motion picture, starring Charlie Hunnam as the offbeat private investigator.