To do this trophy all you will need is,
1. A cop car, you can get a cop car by using your phone and dialing 911, then press 1, after you
do that, wait about 30 seconds and cops will show up, just go up to the car and steal it.
2. guns, you will need guns to kill the criminals,
now after you have all of that, basically if you have a police car, come to a full stop and press L1, after you do this step, a menu should pop up, go to *View current crimes* find one that says, *Criminal on foot*, After you do that it will tell you where to go on the mini map/map,
After you kill the criminal, keep the police car you have and repeat the same cycle, until the trophy pops.
Note: You can only get this trophy by only doing the *Criminal On Foot*, if you do any other current crimes such as gang activity, stolen vehicle, it will not count, so only do criminal on foot.
I also forgot to mention if criminal on foot doesn't pop up in the menu, just exit the car and go back in, then press L1 and open the menu again then go back to *View current crimes* after you do that, if a *criminal on foot* pops up, then click on it, if not repeat the same thing until you find criminal on foot, I hope this helped you.
Also if you want an easier way of obtaining a cop car, you can do this cheat, it won't mess up the trophy for you, as long as you don't use weapon cheats, it won't mess up your game save,
All you haft to do is pull up your phone on the game, and go to dial, then dial 227-555-0100
after you do that, a fbi car should spawn, even though it's a fbi car, you can still use it for this trophy, and after that just get into the car press L1 and there you go.