Goofs

At about 47:30 the cheerleader starts trampolining. The wide shots clearly and obviously show her wearing official underwear that matches her cheerleader colors but once she starts lowering her underwear to tease her boyfriend it's clearly normal non regulation underwear.

At 1h.23 the killer's voice modulator is clearly visible. In the very next cut, it disappears and obviously reappears several, several times.

About 7 minutes into the film, when the kids are making their way to the front of the store, the girl waiting for her boyfriend is shown standing with lots of people streaming past her to get to the door. the man talking to her directly in front of her and pulling her forward is shown surrounded with a huge crowd of people, standing still.

During the riot scene at Right Mart, the jagged glass that cuts a shopper's throat appears from nowhere. The metal frame was bare moments before, all the glass fell with the doors the mob broke down.

Massachusetts state law doesn't allow stores to be open on Thanksgiving.

Christine is trying to escape the killer. She comes across the cheerleader clearly stuffed in a fridge in a plastic bag. There is no way considering the obvious injuries she sustained on the trampoline that she would still be alive. Not to mention being in a plastic bag and the massive pool of blood clearly leaving the fridge.

In the movie they are saying that the Sig Sauer P226 has a safety. In reality, this handgun has no safety.

Plymouth has their own police department, not sheriff's department. Sheriff's departments in Massachusetts don't patrol cities or towns. Most cities and towns have their own local police, while towns too small to have their own departments rely on the Mass. State Police. Sheriff departments in Massachusetts only provide care and custody of inmates in county jails.

Sheriff Newlon's (Patrick Dempsey) uniform clearly has a collar brass that obviously denotes "PD." A sheriff's uniform would clearly have a collar brass marked "SD".

Near the beginning when people are handling the boxes of the waffle Iron in the Right Mart store, the boxes are obviously light and clearly don't contain anything.

When Amanda gets hit in the head by the shopping cart, her body is facing down to the floor. When her hair and scalp gets ripped off, she's lying on her back.

Patrick Dempsey says that he baked the pumpkin pie he brought to thanksgiving. It is in a glass dish and the creases from the aluminum pan it was baked in can be seen through the glass.

When the film shows the multiple surveillance cameras during the Black Friday stampede, two women can be seen fighting over a waffle iron box in the top right camera. The one swings the box at the other woman's head and knocks her down. The camera angle shows a large gap between the two and the box doesn't even hit the woman's face but gets knocked down regardless.

Though Hanover is near Plymouth, they are not the football rival. Plymouth has two high schools and they are the rivals.

In the movie, Plymouth's colors are red and white. In actuality, Plymouth North's colors are blue, white and silver while Plymouth South's colors are black, white and teal.

Before the beauty class chase scene, there are multiple Canadian/EU exit signs shown in the high school that are not found in American schools. The movie was shot in Canada.

As John Carver, dressed as a pilgrim, is chasing Jessica away from the murderous Thanksgiving meal, sheriff Newlon is getting Bobby out of his trunk to set him up to take the fall for the murders. Which isn't possible since Newlon is Carver. Even if he had somehow managed to get ahead of her, there wouldn't have been time to drop the pilgrim look, get his jacket on, get Bobby out of the trunk and get knocked out. She didn't run that far.

At the end of the film John Carver states he wanted to keep several characters alive, including Jessica, but earlier in the film he lures Jessica into the school with the intent of murdering her.

While being attacked, Lizzie is unable to unlock/use her cellphone because of the damage to her face, but never attempts to use the landline phone on the desk next to her.

Towards the end you see the medic shut the ambulance doors. Ambulance doors shut with the left (patient) side first, then right. They shut the right first and the left is seen rebounding and then held shut.