The BAU is faced with a tough challenge while searching for a common denominator among male victims in Montana, making it difficult to profile the killer. Also, JJ must confront her feelings about her sister's suicide.
- Lauren Virginia Albert - Lillian
- Mekhai Andersen - Henry LaMontagne
- Candy Clark - Sandy Jareau
- Abbie Cobb - Claire Dunbar
- Matt Cohen - John Franklin
- Kyle Erby - Stu
- Rosanna Foss - Young Claire Dunbar
- Brandon Garrett - Edward Dunbar
- Evan Holtzman - Colin Baylor
- Mark Holzum - Chris Jensen
- Ellie Jameson - Detective Sandra Carpenter
- Stephen Jared - Darryl Jensen
- Geoffrey Kennedy - Shane Maxwell
- Ted Mattison - Jeff
- Peyton McDevitt - Bartender
- Hank Northrop - Kevin Brubaker
- Diego Rodriguez - Terence Reynolds
- Benjamin Seay - Medical Examiner
- Abigail Wilson - Girl in Video
- "What Have I Done" by Taps
- Jennifer Jareau: "Deep vengeance is the daughter of deep silence." Vittorio Alfieri
- Spencer Reid: "The gift of fantasy has meant more to me than any talent for abstract, positive thinking." Albert Einstein
- Though this is the fifth episode of the season, it aired a week after Boxed In, the following episode, both episodes being scheduled out-of-order.
- The episode's title is taken from the phrase "If the shoe fits, wear it", which is brought up by someone as a suggestion whenever someone else complains to him or her about a generalized remark or criticism he or she received. The suggestion is to take the remark or criticism as applicable to himself or herself. The phrase can often be shortened to "If the shoe fits" and finds its origin in the fairy-tale Cinderella.
- Reid erroneously states that the Battle of St. Scholastica Day occurred in 1335, but in reality, it occurred twenty years later, in 1355.
- ↑ Credited as "Claire's Father"