This list covers all minor criminals mentioned in Season Twelve.
Earl Roy Everton
One of thirteen serial killers who escaped from prison during the events of The Storm. He attempted to flee to Mexico with the help of an accomplice, but was recaptured through the efforts of Luke Alvez, who lured him out by posing as a coyote.
Carla Jean Birch
The accomplice of Earl Roy Everton, who attempted to help smuggle Everton into Mexico. She was arrested by the BAU after an undercover operation led by Alvez.
Seattle spree killer
An unidentified person in Seattle, Washington, who went on a killing spree with an assault rifle. He or she was somehow tracked down by the BAU and either killed or arrested.
Belgian terrorist cell
A terrorist cell of unknown ideology that operated in Belgium. Stephen Walker created a profile for them, but it turned out to be wrong and three undercover agents were killed as a result. However, the cell was still stopped before it could carry out a bombing at a major soccer game.