When you are in the park in the middle of the mall, there should be three convicts in a military style jeep. If not, they will show up later in the game. Try to kill them. The Uzi you find on the balcony inside the mall works best. Kill the gunner first. If you kill the driver, the passenger will start to drive instead. When the gunner shoots, just move to the left or right until he stops. He cannot hit you if done correctly. You only have a second or two before he shoots again. You must hit him with a couple bullets, then start running again. Some time may be required to kill him, but it is worth it. After the gunner is dead, you can take the gun off the vehicle. After you have it, kill the other two convicts in the vehicle. You will get the jeep, an achievement, and a .50 cal. Shoot as many zombies as you can with the bullets you have. After your raid, get in the jeep. You will drop the gun. Look at where the gun was before you took it off. There is an empty slot there. When in the park, follow the perimeter. There is a road that you can turn into to go to a small parking lot. Go to the parking lot. There should be a motorcycle and a red car here. Inside the lot, there is a road that goes down into the basement parking lot. Go down with the jeep. There are a lot of zombies down there. This is a good location to get the Group Photo achievement. When you are done loading the level, look at your gunner slot. A gun should now be there. Drive around a little until you get to a location where you can get out take off the gun. Do not drive far, as you may get lost. Shoot everything until your ammunition is gone. Get back into the jeep. Once again there will be no gun in the slot. Leave by the same way you came in. You can stay down there, but do not just run over victims because there are some zombies with oxygen tanks that will explode when run over. Enough of these will render your car useless and prevent the gun from appearing again. When you get out of the underground lot and load the level again, look at the gun slot. Another gun will be there. Keep going down and up, loading another part of the level to spawn another gun. You can keep doing this for easy kills and an easy shooting 1,000 rounds of ammo achievement.
