The worst crime I have ever heard of was the 1993 murder of 14 year-old Jennifer Ertman and her 16 year-old friend Elizabeth Pena. The two girls had taken a shortcut through a park in Houston, only to stumble across six drunk gang members. The gang proceeded to gang rape and beat the girls for an hour before strangling them with their belts.
The book gives biographical information about the two girls and each of their attackers. The book then tells the story in agonising detail of what happened once the girls took the shortcut through the park. It then talks in detail of how the trial proceeded, with accounts of the superhuman courage and dignity of the family members of the girls.
It is very hard to read the part of the book that describes what was being done to the girls in the park. It is also very hard to read about the insensitive way anti-death penalty protesters kept disrupting court proceedings and kept heckling the victims' family members. Since reading this book, I have discovered that the EU paid for the legal defense of one of the attackers (google Jose Medellin EU).
In short this book is a detailed account of a horrific crime.