The unsub orders "a beer" at the bar, to which the bartender replies, "What kind? We got like 20." This is poking fun at movies and TV shows where characters never seem to order a beer by brand.
To honor a friend who died in Vietnam, Rossi hangs a "W" flag on a wall in his office, and explains to J.J. the custom at Wrigley Field of flying said flag after every Cubs win. Though Rossi as a character is not, Joe Mantegna is from Chicago and is a die-hard Cubs fan.
When Rossi asks J.J. if she's a baseball fan, she responds with "mostly hockey." This could be a reference to the fact that A.J. Cook (J.J.) is from Canada.
Director Leon Ichaso also directed II Mostro (2017), the episode of Criminal Minds: Beyond Borders (2016) that aired immediately after this episode.