Visible crew/equipment: After the press conference, while Emily, Rossi, and Derek are standing beside the SUV, when Captain Lancaster walks over to them we can see the four chalk T-marks on the ground where they all stand.
Other mistake: When Prentiss and Morgan are trying to figure out how the victims were controlled, Prentiss phones Garcia to find a drug that would temporarily paralyze or subdue. Then just as we hear Garcia answering the call, there's a close-up of Garcia's computer screen and we see the picture of five suicide notes, and at this point there have been six victims. Then later, after the seventh victim is found, when Morgan holds the latest suicide note in the close-up, we can see it's the same note that's already been shown.
Revealing mistake: When Agent Hotchner receives a text from JJ while interviewing the suspect, it is actually a screenshot. You can see Camera Roll in the upper left hand corner, "2 of 2" where JJ's name should be, and the Share/Play/Delete banner at the bottom. It is covered by Agent Hotchner quickly tapping on the screen to clear the banners. (00:16:15)
Continuity mistake: In the video of the Chicago robbery they enter the building at 08:27 according to the timecode displayed, but they exit at 15:32. Seven hours is a very long robbery.
Protection - S10-E22
Continuity mistake: The old lady victim under the bridge has a change in clothes. When the shooting happens she is wearing a red jumper and what looks like flowery red top, when the team arrives at the crime scene she is wearing a grey jumper and a white polka dot top. (00:15:54 - 00:26:30)
Suggested correction: The change of clothes happens in every crime scene/flashback to show us the killer's delusion. If you pay attention, it happens with the girl whose boyfriend gets killed and also with the cop/mailman.
Factual error: The train car in which Elle and the other passengers are held hostage is supposed to be an Amtrak type long distance railroad car traveling from El Paso to Dallas, yet on the inside of the car we can see a large poster showing the Washington, DC Metro system map.
Visible crew/equipment: There is a crew member crouching behind the plant during the scene when Reid is searching the house for Maggie. When Maggie just enters the shot, you can see the crew member.
Other mistake: While Hotchner and Reid are talking about Hollow Man and the Mill Creek Killer, Reid's going through the newspapers and when he figures out that the two killers have been talking to each other via the classifieds, there are two closeups of an ad's text. After Hotchner suggests using their relationship against them, Hotch says that Reid's fake ad will imitate Hollow Man's language patterns to send a message to the Mill Creek Killer. Then we hear Reid reading the fake ad they just placed in the classifieds, but the problem is it's the same ad that was shown in the closeups earlier, plus an additional line at the end - "here's my gift to you."
Visible crew/equipment: When Katrina Townsley's driving while talking on her cell phone the unsub is driving behind her, and we see that she's alone in her car, but when the unsub rear-ends her car the second cameraman is sitting in the passenger seat with a handheld camera, filming Katrina's close-ups.
Continuity mistake: When Rossi is telling Prentiss, Morgan, and JJ about the original Galen case, he says that the Galen parents were butchered with an axe, but in "Birthright", he tells Detective Caulfield that they were beaten to death.
Factual error: In this episode Gideon mentions Andrei Chikatilo, and says that he lived in Ukraine (and that this is why he remained uncaught for so long). While Chikatilo was born in Ukraine, he lived in Russia for most of his life, and all of his murders happened here. An expert like Gideon should not make this kind of mistake.
Continuity mistake: When Reid and Lila are in the pool, kissing, he explains how it is wrong that they are out in the open, and in a pool. Lila then kisses him again, and the paparazzo in the bushes takes pictures. In the first shot of this kiss, a close-up of Reid and Lila, her arms are down by her sides, but when seen through the camera, her arms are suddenly around his neck. Back to a close-up, and her arms are once again down in the water. (00:25:30)
Character mistake: Derek Morgan says that he discovered the body of a dead boy in 1991 when he was 15 years old. Later on, you see Garcia searching the computer for personal info on Derek Morgan. According to the computer; Derek Morgan was born in 1973 which would make him 18 years old in 1991, not 15.
A Real Rain - S1-E17
Continuity mistake: At the end when the FBI is going to the apartment where the killer is holding the hostages, Gideon puts on a bulletproof vest while standing next to the car talking to the cop and a second later while he's walking toward the building he puts the vest on again.
About Face - S3-E6
Continuity mistake: Senior SSA David Rossi is clean-shaven in the beginning and middle of the episode. Toward the end of the episode, which takes place over mere days, he has magically grown a full mustache and beard which disappears and reappears in the last scenes.
The Inspired - S9-E2
Plot hole: At the beginning of the episode, PD let the suspect go (twin 1) because they accidentally arrested him for the crimes that his twin brother (twin 2) committed. Hotchner still wants to question twin 1, but a lawyer threatens Hotchner to not go near the wrongfully accused twin 1. However, in the previous episode, FBI and cops pursued twin 1 and twin 1 didn't pull over. It would be legal for twin 1 to be detained on a reckless driving or eluding the police charge.
Other mistake: The boy says he is doing multiplication and the rest of the class is still on long division. You can not do long division without first learning multiplication.
Won't Get Fooled Again - S1-E3
Other mistake: Just after they were finished explaining that you can not tilt the mystery package because it would instantly blow up, they show the little girl at her doorstep holding the package completely tilted. Just when you think that means that this package now doesn't fall into the "explosive" category, they then show the mom freaking out, and later police making the girl hold the package in a completely different (non-tilted) position.
Continuity mistake: While Reid's asleep in the hospital bed, Garcia places four Doctor Who figurines (one Dalek we don't see her place) on the overbed table - two Daleks, Matt Smith's Doctor, and David Tennant's Doctor. In the first shot Garcia's holding Smith's Doctor in her right hand and Tennant's Doctor in her left hand, but in the next shot those two figurines have switched hands.
Visible crew/equipment: When James Charles, the guidance counselor, says, "It could be someone you know, or it could be a stranger you pass at the grocery store," the actors' red T-marks are visible on the floor at Reid's and Gideon's feet. Then when Charles continues to say, "gathering information on the case," we can also see the actor's white T-mark beside the counselor's feet, where he will stand after he introduces Gideon.