These Is A Guide for your help on finding the locations for The Watcher In The Wing Side Mission.
Keep this in mind
so he can be in different locations but the courthouse is the first one (Bold=Important)
Solman Wayne Courthouse
[/previewimg] As soon as Batman completes his first story mission involving Catwoman, you may spot the watcher up on the roof just south of the courthouse. Approach him and he’ll vanish, leaving a symbol behind. Scan that symbol to complete part one of this side mission.
In the eastern part of the Industrial District there’s a ferris wheel. The watcher is waiting at the very top. Again, approach him and scan the symbol after he leaves.You’ll need to have finished the steel mill for the first time before the watcher will appear at this location If you’ve already done that, and the watcher is still absent, try quitting and reloading the game or restarting the game.
In front Of The Arkham City Sign
Look on the roof the building northeast of the entrance to the subway. It’s one of the tallest buildings in the Bowery, so it’s not hard to find. You’ll need to have already interrogated Quincy Sharp before the watcher appears at this location. If you’ve done that, and the watcher is still absent, try quitting and reloading the game or restarting the game.
West Of GCPD
Check the roof of the building just west of GCPD. You’ll need to have already rescued Vicky Vale before the watcher appears in this location. If you’ve done that, and the watcher is still absent, try quitting and reloading the game or restarting the game.
Scanning the fourth symbol that the watcher leaves behind will automatically take you to the Batcomputer screen. Use the right and left sticks to rotate and move the sigil so that its four points match the four locations in which you spotted the watcher. Doing so reveals the watchers final location: the eastern side of the church. Scan the symbol on the wall there to complete this side mission. And you will get the medal