Continuity mistake: In the elderly victim's home, when Gideon is going through the dresser drawers he finds the small frame with the picture of her son, and there is a blue frame lying in the drawer, but in the next shot that blue frame is lying on the dresser even though he never touched it.
Plain Sight - S1-E4
Visible crew/equipment: When the BAU are presenting their profile of the unsub, the actor's T-mark is visible on the floor in the shots facing Captain Griffith, who's sitting on the desk, when Gideon takes a seat on the chair.
Revealing mistake: When Hotch and Spencer are interrogating Eddie, Spencer shows him the three photos of the people he has killed. Eddie makes a gesture as if to speak and points at Spencer, at which point we see a shot of Spencer and he very obviously glances into the camera.
Plain Sight - S1-E4
Continuity mistake: At the very end on the plane, Gideon gives Reid the two tickets as his birthday present. In the shot facing Reid, he holds the tickets facing himself. In the reverse shot, the tickets now face Gideon. (00:39:30)
Continuity mistake: Before the BAU catches the serial killer Carl Arnold, they used a heat sensor and it shows five people sitting at a table. They said there were three adults and two kids, but when they break in the house, the mother and one kid were sitting at the table, the father was tied up nearby, and Carl Arnold and the other child were in the basement. They were found by Derek Morgan right before Carl Arnold threw the child at Gideon, who fortunately caught him.
A Real Rain - S1-E17
Factual error: When BAU walks up the stairs on the way into the courthouse the first time, the John Ferraro building in Los Angeles is visible in the background. They are walking up the stairs toward Los Angeles City Hall. The episode takes place in New York.
Visible crew/equipment: After the three people at the restaurant patio are shot it cuts to the black screen, and in the next shot as the camera pans over the blood stained table, the red T-mark is visible on the ground in front of Gideon's feet. (00:13:15)
Visible crew/equipment: During the plane interior scene after the opening credits as JJ is walking around handing out documents to the team, you can see a gap in the lighting outside and a crew member's face peeking out from behind the white walls. (00:04:00)
Continuity mistake: When Gideon is talking when we first see him, the pictures behind him on the screen change instantly. It should be noted, that when we see the pictures change, there is the audible click and visual delay of a slide change which is not present on the instant change. (00:04:20)
Continuity mistake: Morgan gets a call from BAU and we see him holding his phone in one hand then two. (00:03:40)
Audio problem: As Scott McCarty is shot there is no sound of a shot being fired, suggesting a silencer, however as the assailant's rifle is pulled inside the car you can see that the weapon has no silencer.
Revealing mistake: We see the jet at the end, and the shot is flipped. Note the serial number on the plane's engine. (00:38:05)
Continuity mistake: When Reid is asked if he plays ball, the way he holds the football changes between shots. In one shot he holds it in 2 hands and in another he holds it in one hand. (00:14:30)
Visible crew/equipment: When the camera zooms in on Adam's body near the start, there is a very brief shot of a crew member's hand in the top left hand corner of the screen. (00:02:35)
Revealing mistake: Just as Vincent gets tazered, you can see protective padding that he is wearing. This is not to be confused with his jacket. (00:25:10)
Continuity mistake: When Morgan finds the Glock 19, his grip on the clip changes between angles. (00:14:30)
Won't Get Fooled Again - S1-E3
Continuity mistake: When talking to Bale in jail and negotiating a transfer deal, his handcuffs disappear and reappear between shots. (00:35:05)
Won't Get Fooled Again - S1-E3
Continuity mistake: When in the house and the victim's wife comes in, Hotch returns his ID to his pocket twice. (00:08:00)
Answer: "The Boogeyman", s02e06. Spoiler alert: The kid is Jeffrey Charles and at that point he had already killed 3 other kids. Jefferey basically hated and resented other kids after his mother abandoned him and his father spent a lot of time with other children because of her job. Jeffery would lure kids Into the Woods and then beat them to death with his bat just because of hate, no particular "reason." The scene you're describing, Jefferey agrees to walk Tracy home when her "buddy" leaves her (at this point the FBI announced there's a serial killer on the loose and kids should walk with a buddy). Jeffrey gets mad at Tracy for walking too slow and for complaining, and he takes a swing at her, causing her to flee Into the Woods and have Jeffery chase her.
Bishop73