Book ~ "Dog Spelled Backwards - an Unholy Mystery" (2013) Jill Yesko

From Goodreads ~ Private investigator Jane Ronson suffers from oppositional defiant disorder, the uncontrollable urge to punch first then ask questions later. 

When a rabbi with a shady past offers her a bag of cash to spy on a rival rabbi, Jane jumps at the chance to make what think will be easy money. To get her cash, Jane impersonates an Orthodox Jewish woman and infiltrates a black market kidney ring in Baltimore’s Orthodox community. 

Between Russian gangsters and double crosses, Jane is number one on everyone’s hit list. To save her life, she forms an alliance with a religious woman and confronts a family.

Jane is living with Don, her boyfriend who is a cop, and her dog, Archie.  Her cousin, Lenny, drops a bombshell on her ... she's Jewish, not Catholic as she had been raised to think.  The Rabbi who is helping Lenny discover his Jewishness has a job for Jane.  Rabbi Goldberg wants Jane to investigate the goings on of another Rabbi who is running a black market kidney ring and making some serious money at it.  Going undercover as an Orthodox Jewish woman, Jane must cover up her tattoo, take out her nose ring and exchange her leather and jeans for more subdued clothing.  As Jane investigates, she discovers that not all is what it seems.

This was the second in the series by this author.  The writing didn't seem as raw as the first one, Murder in the Dog Park, probably because Jane, though still cranky, has softened now that she is with Don.  Written in first person perspective, it was from Jane's point of voice.  There were a lot of Jewish references, which were explained, which I found interesting since I'm not Jewish.  Jerome provided some funny comic relief when he goes undercover with Jane as an Orthodox Jewish woman.  As a head's up, there is swearing and adult activity so I would recommend it for a mature reader.