The Perps are one is in the car at the bottom of the river, by the break in the bridge, look closley you'll see it, you'll need to use a crane and a scuba diver. The second crosses the highway with no fight about 3 or 4 minutes in the game. He looks like a terrorist and has a pistol, just arrest him, there will be no fight if you get him there. And I am assuming you are talking about the Airport mission right? Well if so, I do believe that has to be done with an Engineer, there are 2 boxes. One turns off the downed wires, and There is another box for the pipe... Just click use and you will find a like blue coloured box if you use the enigneer then just click it, and he'll cut power, same goes for the pipe turnoff.... The power box is by the exploded area but a little closer to the front of the building by a wall... Hope I helped -Newfoundking