Load up NMPD HQ on any difficulty. Run past the first area, and in the second area you'll see a landing pad with P3 on it on the right. On the ledge overlooking the pad, with a turret that a grunt is on when you enter the area, look for a black square with an arrow on the wall. Jump over the railing beside it to fall to your death, making sure to look back at the wall you jumped from as you fall to see a graffiti face and unlock this achievement.
I've included a video below with loads of achievements. For the Vandalized achievement, start at 10:49