The characters of Kevin Infante and Nancy Porter are from the novel "Every Secret Thing" by Laura Lippman, who is married to series creator David Simon.
While complaining about the official inaction over Marlow's 22 murders, McNulty mentions the public outcry over "one white cheerleader missing in Aruba". This was a reference to ex-cheerleader Natalee Holloway, who attracted a huge amount of media, when she flew to Aruba by private jet, before going missing in 2005.