Corktown by Ty Hutchinson

Book 1 was very good and I gave it 4 out of 5 in April 2023.

Meet the agent with an impossible directive: solve the FBI's most baffling cases. Abby Kane spent her early career putting sickos, psychopaths, and ruthless killers behind bars. After her husband's mysterious death, she moved her family to San Francisco, hoping for a fresh start and healing. What she got instead was a job with the FBI.

Book 1: Corktown

A mutilated body has Corktown residents nervous and for a good reason. Detroit Metro Police recognize the handiwork of the serial killer known as the Doctor. But there’s a problem with that. They locked him up seven years ago. When FBI Agent Abby Kane visits the Doctor behind bars, he swears he’s innocent and not the psychopath everyone thinks he is. Oddly enough, Abby believes him.

Text from GoodReads