Mary Elizabeth Mastrantonio (the actress who plays Kelly Burkhart) was unavailable when this episode was shot, so a body double was used for her scenes.
Opens with a quote, "Stronger than lover's love is lover's hate. Incurable, in each, the wounds they make." This is from Medea by Euripides.
Wu's patrol car number is 421, the same as the episode number.
This is the first episode directed by co-showrunner, Jim Kouf.