[Akuma]

Chameleon Skins are easy to detect. If you're rounding a corners and bullets start being fired before you get there... if someone is constantly looking at walls or ceilings. Or if they open a door and toss a nade in for no reason and get a kill. Or if they throw a nade and it doesn't kill anybody, then they stair at the wall then throw more in or leave.

The code security mod works very well for assuring your suspisions.