Continuity: Sidney is on the roof trying to escape from the killer and she falls off. When she gets up she sees the dead body of Tatum in the cat door and her left arm must be behind her because you can't see it but this isn't what happened when you saw her die. Her left arm was inside the garage and was beside her. Unless if fell off, it should be next to her body.

Factual error: After Gale talks to Sidney and Sidney seems doubtful of Cotton Weary's guilt, Kenny the Cameraman says to Gale, "Do you wanna go live?". Gale is an anchor/reporter for a tabloid-like show called "Top Story" (Sort of like "Current Affair", "Inside Edition", or "Hard Copy"). She does not work for CBS News or NBC News, etc. She does not have the power to "go live" and interrupt regular television programming.

Continuity: After Casey is stabbed the first time, she knocks the knife out of the killer's hands, causing him to start strangling her with both hands. When she fights him off, the knife is suddenly back in his hand again.

Audio problem: When Steve is on the porch and gagged, the killer instructs Casey to turn off the lights. Steve shakes his head and lets out some muffled 'No's. When the lights go out he says one last 'No' but you can still tell he isn't saying it. Even though his mouth is gagged, he makes no body movements to correlate with his shouts like he did before, especially not his jaw. Despite it being dark you can still tell.

Continuity: When Drew Barrymore is running to the kitchen after the patio windows break she grabs a knife. When they show her going through the doors from the inside to go outside her knife's curving blade is pointing toward the celling but when the show her leaving the house through the doors from the outside the knife curve blade is pointing down.

Continuity: When the principal comes back into his office after checking out who was knocking on his door you can see a closet in the background with coats in it. When they change the angle the jackets have moved to a different position.