Increasing Cop rank
Go around checking everyone for drugs and weapons to get +1 Good Cop.
Go to the Hancock Park area in the middle of the map. On a street corner at 2nd and Citrus Ave., you can frisk just about anyone close to or moving to the intersection and almost always finds drugs or weapons on them.
Go to Ozone Ave. in Venice. Just about every person there will have weapons or drugs.
Go to 4th and Hill. Just about everyone there has drugs or guns.
To increase your Good or Bad Cop rank easily, replay a stealth mission and choose your attack accordingly.
To increase your Good Cop rank, walk on any street near from somebody. If they look at you, it means that they are clean for drugs or weapons. If they do not look, they have illegal things like guns or drugs. Arrest them and you will hear a sound of good cop. Note: Do not try this with people who are talking by a phone.
There is a street where almost all of the people you arrest will either be carrying drugs or weapons. To get there, take Highway 10 east or until you get to where Highway 10 and Highway 405 cross over. It will be near the east side of the map. Take Highway 405 south. When you merge with Highway 405, take the very first road off Highway 405. It will be backwards, but it should lead to National Blvd. When you get off Highway 405, you should turn left. After you pass Sawtelle Blvd., go down until you are about slightly halfway past Sawtelle Blvd. Get out of your car and frisk someone. They should have drugs or weapons.
Play a stealth mission with a lot of people and use only stun attacks, then complete the stage. Wait until the auto save is finished. Then, exit to the main menu and resume the game. Play the stealth mission again. Repeat until you get the desired good cop rank.
In the Hancock Park area on Highland Blvd. between 3rd and 2nd Street, mostly everyone has illegal drugs or weapons. The street is located just above the "O: in Hancock Park on the map.
In Hancock Park on Highland Blvd., between the white picket fence and the green shrubs, most people you stop will have illegal drugs and guns, even those on their cell phones.
On Second Street between Irving Bvld. and Lorraine Blvd., most everyone you stop will have drugs or guns.
Start a fight with a pedestrian, and when you stun them, knock them over with a special move. Before they get up, take out your guns. Once they are standing, they will surrender and you can go in for the arrest. Note: this will not work if the
pedestrian is carrying a gun; frisk them before you start fighting.
If you are in Venice, immediately start driving towards the apartments by the ocean (refer to the map). These streets are somewhat small, so they may be easy to miss. Drive around and you will find a street called Dudley. Everybody there is
carrying drugs or weapons. Note: Dudley is by Ozone.
Everyone along Ocean View in Venice, at the far southwest on the map, is carrying drugs or weapons. You can go up each street along Ocean View up to one block and everyone there will have something illegal on them. Also, armed muggers do not fight back on those streets. Just draw your gun and they will drop their weapon.