Factual error: In the beginning of the episode, the neighbors do not hear shots fired because the murderer uses a homemade silencer. At the end, when they find the murder weapon in the dumpster at the murderer's apartment, it is a revolver. Silencers (homemade or otherwise) do not work on revolvers because the gas escapes from the sides, not exclusively the end of the barrel.
Factual error: The con is said to be electrocuted. But the jump start cables are connected to handcuffs which would short the electrical circuit and most probably melt the handcuff chain, but wouldn't electrocute the victim. (00:02:50)
Answer: The networks are now having winter breaks. A mid season end of new episodes, when they come back after the new year, it picks up as if several months have gone by. Beckett suggested Valentine's Day as a "chick flick" to watch as she is moved in. Also some episodes are not scheduled to air in order.