Along Came a Spider (2001)

Revealing: After the woman is strangled and the people come in trying to find the little kid, the dead woman is clearly seen blinking.

Factual error: As the kidnapper is watching TV, we hear a news anchor describing the kidnapped child. She is described as 12 years old, 3 ft. 5 in. tall, and 52 pounds. This is the size of a child half this age. A 12 year old of this size would be freakishly small, which this character is not. And as we see her throughout the movie, she is easily approaching 5 feet tall and in the 70 - 80 pound range.

Continuity: In the opening scene where Alex's partner is in the car with the bad guy, when she pulls her gun and he hits the brakes sending her into the dash she is not wearing a seat belt. Immediately after, when the car goes over the side of the dam, the shot looking down on her shows her with a seatbelt on, the reason she didn't fly from the vehicle.