My actual rating is a 4.75 stars. (Now 4 stars after a couple weeks) I loved the main character Lucy, she took no śĥiť from anyone, and she was a strong lead. I loved how the story makes me question the ethics of "how much can we talk about Murders without getting desensitized" and the answer is not many. The difference in emotion I had between reading a murder mystery about a 30-year-old guy and about newborns is incredibly different. 
We usually have different feelings from when we hear about a random 30-year-old guy being murdered, and newborn babies or the elderly being murdered, and the book really makes you think about that in my opinion. It was well written and I liked the relationships between Lucy and Sabrina, and her son. I don't have any complaints having to do with the story to not rate it 5 stars, I just feel like there's something missing to give it that push to make it perfect. Overall, I recommend this to anyone who likes gruesome murder mysteries.

EDIT: I rate it 4 stars now