Continuity mistake: When Reid is talking there's a big crack at the top of the window that might be a problem since they're supposed to be flying. Then a few seconds later they cut back to him and it's filled with putty. (00:05:00 - 00:06:00)
Other mistake: A mugshot of a suspect is showing with some personal information. Name, license number, address, etc. The field for "Home address" shows a valid address but "Work Address" shows "Male." The correct field title should be "Sex." (00:40:00)
Continuity mistake: When Garcia accesses the bank's page online Prentiss gives her the account number login, 1552 9384 6729, and we see Garcia typing it correctly on the screen with the password, but when it cuts to the account's page showing deposit and balance, we see in the balance box the account number's last four digits are 7629, not 6729.
Continuity mistake: While Morgan and Prentiss are at the crime scene talking to the homeless man, when Morgan moves the tent and finds the text written on the wall, the homeless man smudges the text with his fingers, but when Morgan sends a photo of the evidence the smudges and text differ.
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