Walker

Detective Walker (first name unrevealed) is a minor recurring character who first appeared in Penelope.

History
Absolutely nothing is known about Walker, other than he worked as a detective for the Metropolitan Police Department. He first appeared in Penelope, where he assists in the security detail for Garcia at her apartment after she is shot and nearly killed by a serial killer. When the unsub attacks Garcia's apartment, in the process killing a police officer patrolling the area, Walker is visibly upset about the shooting. He isn't seen again until Nameless, Faceless, where he assists the BAU when a man begins killing middle-aged Hispanic men and threatens to kill the son of a doctor named Tom Barton. When the doctor's son goes to his high school for safety, Walker helps the BAU in securing the area and then evacuating the school when it is feared that the killer might go on a killing spree.

Appearances

 * Season Three
 * "Penelope"
 * Season Five
 * "Nameless, Faceless"