The first victim is attacked holding a beer bottle removed from a 6-pack. As he hits the floor off screen the sound of the bottle breaking is clearly heard. Next, as the FBI is at the crime scene, you see the same beer bottle intact standing upright in an evidence bag placed next to the other 5 unopened bottles in the 6-pack.
When the third victim is in the house there's a clock from the recording camera. When he's going to the bathroom, the clock is at 2:51:16. There's a cut just when he's going to be beaten and after the cut the clock is at 2:50:16
Near the end of the episode, as Charlie stands in front of a large electronic map and explains his theory, Megan (who is seated) comments on what he's saying. When she's shown from the front, she's gesturing with her right hand - but when she's shown from behind, it's her LEFT hand that's doing the gesturing.
When Amita and Megan are looking into the room where Charlie is making the phone call to NASA, there is no nameplate by the door. When the camera moves to Amita, there is a nameplate saying "L. Fleinhardt" behind her. Then as they leave, the nameplate is missing again.
When Amita is running the "HOUSE_FOR_SALE_MURDERS STATISTICAL MODEL", the computer screen shows some spelling errors: "CORRELATION (?muder,?house)" probably should be "murder"; and "CONSIDERING vivtimAddress" should read "victimAddress". Misspellings are not uncommon in computer programs, but inconsistent spelling would cause errors.
At the end when when they are watching the space shuttle launch on TV, you can hear the announcer say "Liftoff Challenger making its way to the International Space Station....". The Space Shuttle Challenger was destroyed in an accident in 1986 and this occurred in 2006, so this could not be the Shuttle Challenger.
When Megan is talking to the first victim's wife, the wife serves coffee/tea. However, if you look, the cups are obviously empty and are a pristine white with no trace or residue of liquid in them.