It is revealed in this episode that John Munch has been promoted to sergeant, as he mentions that he took the sergeant's exam on a bar bet. In the Homicide: Life on the Street (1993) episode Fire: Part 1 (1995) in 1995, Munch had planned to take the exam then but failed to show up after he could not find his lucky socks that morning.
This season, photographs of cast members during opening theme/credits are all outdoors, not indoors.
Six-eyed sand spider is a term for any number of spider species belonging to the genus Hexophthalma. Most are found in desert environments in Southern Africa, the most commonly encountered species is Hexophthalma hahni. All spiders in this genus have a dangerous, and potentially deadly, necrotoxic venom, similar to the venom of the commonly known brown recluse spider, only far more potent. Necrotoxins cause massive tissue damage and death, the skin around the bite wound becomes black and necrotic (rotten). While there are no known deaths caused directly from the venom itself there are a number of deaths on record caused by secondary infections that begin in the bite wound and spread to the rest of the body, Clostridium infection being a common example, which is one of the bacteria responsible for the deadly condition known as gas gangrene.
Cragen is temporarily suspended as a result of the illegal actions of his detectives, specifically Benson, Stabler, and Fin, which were brought about in the previous episode, Screwed (2007). These include Fin's step-son, Darius Parker, being acquitted of murder in the aforementioned previous episode, Benson aiding her then fugitive brother in the episode Florida (2007), and Elliot covering up his daughter Kathleen's DUI in the episode Blood (2005)