Street Criminals are NPCs that are programmed to commit crimes. They create a more "complete" environment in the city by simulating typical street crimes making the game more realistic and brutal.
Grand Theft Auto III
The criminals in GTA III come in two varieties. One of the criminals looks strikingly similar to members of the Southside Hoods, except he has a different face texture and wears a brown jacket, as opposed to the Hoods' red and purple jackets. The other criminal wears a hat, a black shirt with white sleeves, and blue "Camo" shorts and is a white male.
Much like in GTA 2, they will steal any civilian or gang vehicle that they can access, including the player's vehicle. They can also be seen pickpocketing pedestrians, including each other, although the criminals who have been robbed will strike up their fists and stand, who usually run away, or chase and fight them. If the one points their gun at them, they will give them the money that they robbed from the pedestrian.
Grand Theft Auto: Vice City
Like in previous games, the criminals in GTA Vice City come in three varieties. One is a black man with a black leather jacket, blue jeans, black gloves, and white sneakers. The other is a white man with a reddish-colored leather jacket, blue jeans, and black shoes. The last one, although the rarest of the three, is a Hispanic man, resembling a Pimp, with a red leather jacket, black pants with red leather stripes, and a sombrero.
The first two bear a resemblance to the Sharks, although with cleaner attire. They can often be seen in groups in the North Point Mall at night, except for the Hispanic man, in and outside the mall. They really don't rob people of their money, rather, they will steal any civilian vehicle that they can access, including ambulances, helicopters, and the player's vehicle. They will not attempt to steal motorcycles, scooters, gang cars, law enforcement vehicles, apart from Rhinos, or fire trucks.
They might even commandeer a Maverick or other helicopter, if the player lands one near them and waits long enough for one of them to notice the aircraft. However, unlike later games, they won't fly away. Instead, they will drift forwards along the road with the rotor blades spinning. This is the result of the game's engine being unable to implement proper AI for normal NPCs flying helicopters outside of missions. This can become a serious safety hazard, since the blades can severely damage anyone that comes near it, including the player.
However, if a police officer sees them carjacking, or just walking in general, they will attempt to stop them. The player is rewarded a "Good Citizen Bonus" of $50, if they choose to help the officer. There is a glitch, where the player can repeatedly stomp on the criminal and receive the $50 bonus until the body disappears, even if the criminal is dead. This only applies, if the player uses their fists or a melee weapon. If the player discharges firearms under any circumstances near a cop, they will receive a star on their Wanted Level.
Street Criminals often enter the Washington Beach Police Station, and get shot by the police officers. Members of the Patrol Invest Group also don't take kindly to them and will sometimes try to shoot the street criminals, but only if the street criminals attack them.
The cops pursuing them can be up to three officers against one street criminals, or more If there are S.W.A.T, FBI or even the Army, and they will not give up pursuing them unless the protagonist, Tommy Vercetti, commits a hostile action near an officer pursuing them, and the cops will immediately turn against Vercetti instead. In fact, all law enforcement in Vice City will pursue them, similar to gang members.
Grand Theft Auto: San Andreas
The criminals in GTA San Andreas will try to steal any vehicle, including the player's vehicle. However they will not steal any law enforcement vehicles. They may have hidden weapons, such as a knife or a pistol. Like in GTA Vice City, if a police officer sees, they will attempt to stop them. Unfortunately, the player no longer receives a "Good Citizen Bonus" for helping the officer, in fact, the player is more likely to attain a wanted level by doing so, possibly because it's considered interfering with police affairs. Nevertheless, the one can still help the police by blocking the criminal's car with their own, or bike, or even kill the criminals when out of the cops' sight.
There are four criminals that can be found throughout San Andreas. The first one is a black male dressed in a dark blue checkered shirt, a gold chain, forest-green chonglers, and white sneakers, and is mainly found in Los Santos. The second one, also found in Los Santos, is a hispanic male wearing sunglasses, a plaid tan shirt worn in a "cholo" style, khaki pants, and black sneakers. The third one is a San Andreas Biker, a white male with sunglasses, a gold chain, fingerless gloves, a leather motorcycle jacket with a gray T-shirt underneath, tan pants, and motorcycle boots. The fourth and final one is a white male who appears to be a punk rocker, sporting a red mohawk, a customized motorcycle jacket with a gray punk rock T-Shirt underneath, tattooed arms, ripped jeans, and maroon combat boots. The punk is the rarest of them all, exclusive to Las Venturas and only spawning at night.
Crack Dealers can also be seen throughout San Andreas. They are identifiable by their clothes and their actions. They wear either jeans and a black tank top, or a light-gray hooded jacket. They stand in the same place for a long period of time and deal to other pedestrians. They carry a Pistol and a large amount of cash.
Although not necessarily "criminals," road ragers are also a fairly common sight in San Andreas, particularly in rural areas. If someone crashes into them, they will exit their vehicle and attempt to fight or even kill the other driver. Sometimes, they will be armed with a melee weapon, such as a shovel, golf club, or a baseball bat. If they are successful in killing the other driver, they will usually just get back in their car and drive away. Occasionally, a police chase may randomly appear between armed felons in a car and police officers. The armed felons will do a drive-by at the cops during a chase.
Sometimes, a police officer can be seen running after a random NPC, who can be heard screaming "I didn't do it!" or "It wasn't me!" and some other things like that. However, unlike in Vice City, when the officer catches up to them, he will then simply walk away. Strangely, the NPC will still run away screaming. A police chase may also start if a motorist hits a police vehicle whether it be accidental, on purpose, or caused by someone else pushing the car. The police will give chase to whoever hit their car and will attempt to stop them. Once they are stopped, the police will attempt to drag the pedestrian out of their car and will open fire on them regardless of if they are armed or not. Police will also shoot members of certain gangs on sight, unless they are in a vehicle.
Random NPCs may attack an officer for some unknown reason, and the officer will take out a pistol and shoot at his attacker. However, the NPC may have a weapon of their own, such as a pistol or a knife.
Street criminals appear in several other Grand Theft Auto titles. However, they will remain mild rather than hostile, until of course, they are intimidated or injured.