The title of 'Night and Fog' refers to the Nazi decree of Night and Fog (Nacht und Nebel) issued in December 1941 authorizing the Gestapo to arrest political opponents to the Nazi regime. It also allowed the shooting of sabateurs and commandos without trial.
This episode appears to be based on the 1970s-1990s John Demjanjuk (a.k.a. "Ivan the Terrible") case. John Demjanjuk (born Ivan Mykolaiovych Demianiuk) was a retired Ukrainian-American auto worker, a former soldier in the Soviet Red Army, and a POW during World War II. John Demjanjuk was accused of being Ivan the Terrible, the nickname given to a notorious guard Ivan Marchenko, at the Treblinka extermination camp during the Holocaust. In 2011, he was accused of war crimes as a different guard named Ivan Demjanjuk, who served at the Sobibor extermination camp. Already in 1944, a cruel guard named "Ivan", sharing the distinct duties and the extremely violent behavior with a guard named "Nicholas", is mentioned in survivor literature (Rok w Treblince by Jankiel Wiernik, translated into English as A Year in Treblinka in 1945); however, very little is known about Ivan Marchenko.
Dalmane is one of the brand names of Flurazepam, a long-acting benzodiazepine sedative similar to diazepam (Valium), only more potent and longer lasting, it is commonly used to treat insomnia, specifically for people that have trouble staying asleep. Short acting benzodiazepines like diazepam are used in people who only have trouble falling asleep.
Chris Noth (Detective Mike Logan) & Eric Bogosian (Gary Lowenthal) also worked together on three episodes of The Good Wife (2009) and 21 episodes of Law & Order: Criminal Intent (2001).
Chip Zien, who plays Mr Green in this episode, previously played a homeless man in Happily Ever After (1990) (episode 1.5).