Blooper

During the final battle between the gangs and Kersey, a small two-story wooden structure is seen burning out of control on one of the neighborhood streets. While firemen fight the flames, the facade collapses into the street and the whole structure is consumed in fire and smoke. In several of the following battle scenes however, the structure is seen unscathed and totally intact.

The Cuban's body is later seen next to a building several stories taller than the one he fell off of earlier.

The Cuban's body pivots around head-for-foot between when it falls on a car and when the police investigate it later.

During the riot, the cops have six-shot revolvers but fire more than six shots without reloading.

When Bennett takes Kersey to Charlie's room it is clearly night, but towards the end of the scene we see a shot of Bennett near a window and it is daylight outside.

The Browning 1919A4 machine gun is recoil operated. Without a solid mount--pintle, tripod, bipod on the ground--it is guaranteed to misfire within a few rounds and require cycling the action again. Long bursts as shown are impossible when hand held.

In the end when Bronson fires the LAWs rocket; The back blast would have been confined to the room and killed him and did not travel far enough to arm the war head.

While Kersey is having dinner with the Kaprovs in their first-floor apartment, he goes out and shoots the two car thieves. Yet when he returns from outside, he's walking down from upstairs. He should have been climbing up from the ground level.

When Kathryn's car rolls downhill and slams into another car, both vehicles spontaneously explode. This is extremely unlikely at these low speeds (both cars were going at around 30 mph). Thousands of people are killed in car crashes every year, but at much higher speeds and without any explosions. Although gasoline is very flammable, it needs to spill outside and a flame to ignite. At 30 mph crashing cars do not produce enough heat for ignition, especially when gas tanks are in the rear of vehicles and even if gas is spilled, it ends up on the ground, not on top the hot engine block. Since Kathryn regained consciousness before the crash, she would've had plenty of time to escape.

Charlie (Kersey's friend who was killed) and Bennett (who helps Kersey) are supposed to be neighbors living in the same apartment building. However, their apartments are as different as they can be. Slum buildings often have identical flats. And even if some of them do differ from the others, Charlie's and Bennett's apartments are wildly different. Bennett's ceiling is almost twice as high as Charlie's, and his living room is also more than twice the size of Charlie's.

(Incorrectly regarded as goof) Bennett shows Kersey an old US Browning .30 lMG in his cupboard. When the punks attack him, he suddenly takes out a German MG-42. Bennett did mention that he had 2 machine guns.

The police chief explicitly states that handguns are illegal in New York City early in the film. Yet in the climax, many concerned citizens have their own handguns. Where did they get them from, if ownership of them is illegal in the city? It's never stated that they acquired them legally. It's also possible Kersey, off-camera, connected them with someone who could've sold them products to defend themselves with.

When Kersey shoots Giggler, he shoots him from behind. Yet when the police examine the body, there's a small exit wound. With a Wildey Magnum, the exit wound would've been much bigger than the entry wound.

(at around 82 mins) When Paul shoots a thug fake blood splashes on the camera lens.

When Kersey is in detention and the skinhead tries to blindside him, he suddenly turns to his left and begins to double over well before Kersey has a chance to hit him

When Paul fires his Wildey magnum at the thugs on the outside apartment stairwell, as he fires the gun, the slide pulls back, But when he fires again, the slide doesn't go forward to reload for the fired shot.

There are several occasions where thugs fall down as though they have been shot when it's quite clear that no bullets have hit them.

After the final fight is over, police captain Shriker tells Kersey to leave town, saying "They (the police) will be after you. Go on, get out. I'll buy you a few minutes." But in the final shot, we see that instead of leaving right away, Kersey has used those precious few minutes to neatly pack his suit and clothes, which he's carrying as the credits roll.

When Kersey finds boot prints in the apartment, they are not the prints of someone who was walking. Rather, it looks like the prints were made by someone jumping repeatedly with both feet at the same time, like playing hopscotch. Furthermore, it looks like the person has walked on fresh black paint before breaking in.

When Kersey opens up the box with the LAWS missile launcher, he removes it and then loads one of the self-propelled missiles into it backwards. If it were fired in that orientation it would either blow up the launcher or exit the back of the launcher likely killing the person firing it.

When Bennett tries to fire the first machine gun and it jams, the bullets on the ammunition belt are wrong: they're a different kind and size from the ammunition belts of the same gun in the other scenes. For one thing, they appear to be too large, they're bigger than the slot on the gun (hence some of them appear to be removed, to fit the belt in). They're also quite distanced from each other.

The mob leave celebrating, after the thugs have just killed a rival gang member, and we clearly see that someone in the front picks up a toilet plunger. How would a stick with a wide rubber end be used for illegal assault purposes? It can give a germaphobe a nasty scare, but other than that, its potential to inflict harm is severely restricted.

Eli complains that he doesn't want to close his window, because it's "90 degrees out." All the characters are dressed in clothing more appropriate for early spring/late fall.

Charles Bronson is shown mail ordering his gun and an M72 LAW. Direct mail order firearms has been illegal in the United States since 1968.

At the beginning of the film, Kersey said that he'll give the cab driver $20 if he gets him out of the traffic jam, when the cab driver says "Thanks man", his mouth does not move at all.

Lips of policemen beating Kersey don't move at all to match on-screen dialog.

During the showdown when Fraker firebombs a building and a man and women tumble down a flight of stairs in flames, the man's hair is clearly soaked in fire retardant.

Kersey shoots a man through a garbage can. As the man falls over, an undetonated squib can be seen on the far side of the can.

When the gang rolls Kersey's car down the road and it crashes at the bottom of the hill and explodes, supports are clearly visible holding up the car as it's burning.

Camera shadow visible as Kersey and Shriker run down the street shooting thugs.

Towards the end of the film a gang is pursuing Paul rivals down a street lined with Stanton Staveley concrete lamp posts. These are common in the UK, which gives away the location as South London. These types of posts are not found in NYC and are extremely rare in the USA.

(at 25:32) The night Kersey moves to Charlie's apartment, he looks at the pictures on the wall. Among them is a picture of two uniformed soldiers in a military jeep: Charlie and Kersey as young soldiers (a photo of a young Charles Bronson is clearly recognizable). However, as mentioned many times since the first Death Wish movie, Kersey was a conscientious objector. He was never in the army.

Eli Kaprov casually reads a magazine and acts surprised when his wife informs him that Mr Kersey just shot some of the creeps.He obviously didn't hear a .30 cal full auto machine gun and the screams of dozens of punks being shot and returning fire just 10 feet from his window but his wife did.

Kathryn claims she lives in a basement, yet the interior of her house is clearly that of a standard, ground-level house.

Bennett asks if Kersey loads his own shells for the Wildey .475 Magnum despite just watching Kersey weigh gunpowder,fill the casing and use a bullet press.

When Kersey is caught by the police early in the film, an elderly police officer takes his gun and personal belongings, putting them in a nylon bag. In the meeting scene (around 14.40) the same officer is named as "Captain Sterns." There is no way a police captain would do something as simple as bagging a suspect's personal belongings, which is a job to be handled by the lowest-ranking officer.