It was okay. I think by 60 percent I had figured it out. It was interesting to see why thought that I wasn’t sure about until the reveal.
I found Mariana off and I wasn’t sure why she was allowed to be involved like she was, and some of her actions were very questionable.
Mariana is clearly not stable throughout the book. And some aspect are...  unrealistic ~~ Spoiler ~~

being able to see the crime scenes while not being police (that guy would and should be fired) and at the end seeing her niece. She clearly has no respect for authority and what she gets away with it every step she takes. It extremely unrealistic. Girl should be in prison or fined at this point.

 
This book was neither good nor bad, I did find it a different to my usual reading and easy on the brain.