This is Roper bringing you a complete 100% walkthrough of Hitman: Absolution. This video will get you the following challenges in level 20, Absolution:

Chameleon
Evidence Collector
Infiltrator
Suit Only
Wolf in Sheep's Clothing
Heart of Stone
Crossed Out
Numb
Arm's Length Principle
Predator
It Ain't Over Until...
The Higher Ground Part 1
The Higher Ground Part 2
The Higher Ground Part 3