The Zachary Goldman Mysteries by P.D. Workman
P.D. Workman has created a deeply flawed but very compelling character in Zachary Goldman. His background is tragic and his ability to interact with the world and appear "normal" is one of his greatest daily challenges, and both informs and hinders his work as a private investigator. I recommend starting with the first book in the series, She Wore Mourning. The central mystery is heartbreaking—a "cold case" that's the drowning death of a five-year-old—and there are plenty of twists and turns on the way to solving it. The dead child's parents are fascinating to read about, needing to keep it together through their non-neuronormative conditions. Workman writes these characters very well: their conditions don't define them, and the reader easily sees the real people where society might only see the conditions.
By the way, if you're a cozy mystery fan, P.D. Workman's book Gluten-Free Murder appears in the Cozy Winter Reads six-book set, available for $2.99 for a limited time.