When Reid puts three red pushpins into the map to show the locations of the three homicides, they roughly form an equilateral triangle, with two of them next to a wide diagonal road. After Gideon suggests that Reid and Prentiss visit nearby homeless shelters, the location of the pins has changed, and only one is near that road.
As Spencer and Emily are talking in front of the homeless shelter, Spencer's book bag changes positions from across his body (front shots) to hanging on one shoulder (shot from behind) and back again a few times.
The US Rangers used M16A2 during the war in Somalia, not M4s, which they had in the flashback.
Hotchner asks for a dozen UHF radios, but the radio shown is set to 14,160.00kHz (14.160MHz) which is HF and nowhere near UHF (300MHz to 3GHz).
California license plates and Los Angeles street signs are seen in what is supposed to be Houston.
The team is supposedly in Houston, but at 5:34, the buildings in the background are clearly Los Angeles. The City Hall building is on the far left side.
When Spencer Reid rather angrily closes the window at the police station to shut out the noise, the shadow of the boom microphone briefly passes across the wall next to him.
When Prentiss presents her badge to the shelter administrator, it's upside down.
At the end when the F.B.I. and SWAT teams are trying to apprehend Woodridge, there is a construction crew working just down the street. The police would have cordoned off the entire area for at least a couple of blocks, preventing any civilians, including the boy, from entering the area.
Hotch is briefing the local cops and states that the suspect is 6'1" and 195 pounds. The sheet that he hands out shows the suspect is 6'2" and 195 pounds.