Grand Theft Auto: San Andreas/Vigilante

Prerequisites

 * Vehicle: Any law enforcement vehicle (Police cruiser or motorcycle, SWAT van, etc)

Tips
The Police vehicle that you pick can play a major role. The police motorcycle (HVP-1000) allows for faster travel and steering than the cruiser, and allows the player to fire a micro SMG forwards while driving. Recruiting up to 3 gang members to accompany you on the mission may help. Every level adds one person to be eliminated, and when you have more than four people you will have more than one vehicle. 1-4 people will be in the same vehicle, 5-8 will be divided into two vehicles and 9-12 into three. More than 12 people will not appear in any level.

If you have finished the flight school with all gold awards, "The Hunter" AKA "The Ultimate Vehicle" (an Apache helicopter) will appear at your desert airbase. The hunter allows superfast travel, plus it can fire rockets and minigun at enemies, allowing a quick elimination. Eliminating enemies using the hunter's machine gun will also not attract any police attention. It is relatively easy to reach any vigilante mission with this helicopter.

The Hunter gunship can also be obtained by entering the "Heli Hell" race tournament at Las Venturas Airport. You'll start in Los Santos; just fly directly to the Verdant Meadows airstrip in L.V. and store it in the hangar there, or fly it to your race-trigger point at LVA, land, jump out, wait for the timeout, then exit the race. That's faster than storing, since you already have it sitting next to you for the Vigilante mission.

Another possibility is getting a Rhino tank (Find a ledge in the desert near a street and get all stars by killing policemen, when the military gets called steal a tank and get it to the airfield garage and save) It is nearly indestructable and it can fire its main gun.

Glitch
There is a glitch regarding vigilante missions that renders them extremly easy to complete, simply get a police car (General consensus is that it MUST be a police CAR, but the police bike has worked for some people) and activate the mission. Next go into a fast food resturant or bar and walk around until the message comes up that the criminals have been terminated. Go back into your police car to start the next level and then repeat the process. This also sometimes works when visiting a clothing store. It sometimes works in a 24/7 as well.

I've found that doing this glitch in Los Santos doesn't work well, because the baddies are often spawned up in the rural areas, and the cops don't get to them quick enough.

The trick is to wait until you're in San Fiero, and start the glitch near the north end of the city, just south of the bridge, like at the Pizza joint there. All the baddies spawn downtown, and the cops get to them rather quickly. Yeay.

Rewards

 * Finish level 12 to increase maximum armor to 150.