A Good Girl's Guide to Murder

Too tense for me.

I always include major spoilers (hidden), to help with my memory  issues. Read them at your peril! 

17 yr old Pip investigates the 5 yr old murder of a student at her school, assisted by the brother of the supposed killer. Cleverly constructed. Didn't warm to the characters much. The murderee was A drug dealer, bully, and heartless to her sister, due to miserable upbringing. Sal, presumed to have killed her,  and to have committed suicide,  was murdered  himself