This is the best location to get this achievement.
1 - Have access to the jetpack.
2 - Kill some civilians below to get the police's attention.
3 - Jetpack to the top of this building and wait for the 2 cops to arrive to the roof.
4 - Each wave will spawn on top of you, make sure the wave drops at the far side of the building (not the center.)
5 - When the drones come out to play, shoot an initial rocket to quell the cops then let your shield do the rest of the work.
Note: Cops can use the elevator to teleport away, you may need to snipe them.