Goof (continuity error): At the beginning of Megan's and Dr. Hunt's conversation on the bridge, the strap of Dr. Hunt's purse lies alternately on her shoulder and on her forearm.
Goof (errors made by characters, possibly deliberate errors by the filmmakers): Lacey asked Peter who he was and he introduced himself as if they'd never met. Yet she'd interviewed him and all of Megan's colleagues two episodes previously for her school project.
Goof (errors made by characters, possibly deliberate errors by the filmmakers): In the opening sequence, the doctor was checking for vitals to see if the girl was still alive. Why then did he need to check her blood pressure?
Goof (factual errors): After they find the room in the house where Amy lost all her blood they smell bleach, which indicates that someone cleaned the room. They use Luminol to find the blood stains on the floor and walls. But if someone uses bleach to clean up blood, you would see smears from where they cleaned as Luminol reacts with bleach as well. But the Luminol shows no such smears, just the original blood stains. This would indicate that no cleaning was done.
Goof (continuity error): Although Peter throws the serial killer directly over balcony rail, the killer ends up about 20-25 feet down the sidewalk from where he should have landed.
Goof (errors made by characters, possibly deliberate errors by the filmmakers): A character radios in the license plate of vehicle used in a drive-by shooting. Using the phonetic alphabet, he finishes by saying "X-ray Tom Tom". It should be "X-ray Tango Tango".
Goof (continuity error): The finger Kate uses to examine Sergei's scar jumps from pinkie to index.