Corrected entry: When interrogating the Uncle, the agents say that Emily is left handed (reinforced by when they throw a ball to the uncle and he catches it with his right hand). In a later scene, they show Emily drawing the black and white picture for the "unsub" with her right hand.
Corrected entry: In season 4, episode 9 "52 Pickup", in the scene where Jordan is describing the case, the writers made a large error concerning the M.O. of the UnSub. Agent Jordan states that the UnSub makes his victims clean up their own murders, and they arranged the cleaning supplies in a triangular pattern. The cleaning supplies were bleach, ammonia and garbage bags. This would be excusable if she hadn't also added that both bleach and ammonia were found under the victim's fingernails. If you mix ammonia and bleach, it has the potential to create one of three very dangerous chemicals. One was used in WW1 (chlorine gas), and the other two are highly explosive (Nitrogen trichloride and hydrazine). However, all the victims died of exsanguination (blood loss). This isn't mentioned by Dr. Reid, who has a Ph.D in Chemistry.
Corrected entry: Carrie is seen in the restaurant wearing flip-flops, but when she exits the house the next day, after she had been drugged by the invaders the same night, she is wearing white sneakers. Since she would have been unconscious all night and is obviously disoriented, its very unlikely she would take the time to put on socks and shoes to go for help.
Corrected entry: We are told that an analysis of the DNA from the hair sample held in the evidence bag shows it came from Rebecca Bryant, the first victim of the serial killer they are hunting. Later we see a clear shot of the hair - it is a lock of hair, cleanly cut off, and tied with a ribbon. There are no roots, which are the only parts of the hair that contain DNA - hair shafts do not. They would not be able to harvest DNA from this hair sample.
Corrected entry: Previous episodes of the series have established that the series takes place in present day, well into the 2000's. The models of cell phones and cars used, references to the 9/11 attacks, etc. In this episode, both Jacob and Sarah Jean are shown to be executed in the electric chair. The problem is; Florida has not used the electric chair for executions since July 8, 1999. Ever since, the state has used lethal injection for capital punishment.
Corrected entry: Episode: "Sex, Birth, Death": In the scene where the agents are called to the conference room and start talking about the case, the camera pans the room and shows a white board with information written on it. At the top of the board, in bold letters and asterisks around it, is the word MANDITORY. Was it MANDATORY for them to misspell this word?
Corrected entry: When the professor gets killed, a kid is shown trying to drink out of the water fountain, but the water is turned off. Gideon figures out that there will be no water to the sprinklers, so a fire is soon going to be set. In real life, fire sprinklers are not connected to the main water supply. Sprinklers are on a separate pump. (00:15:00)