This list covers all minor criminals mentioned in Season One.
Eric Miller's foster parents
A foster couple who physically and sexually abused murder suspect Eric Miller while he was under their care as a child. It is unknown if they were ever prosecuted for the child abuse.
A mentioned incarcerated child serial killer. At the beginning of the episode, Elle is on a train to Texas to interview him. His file shows that he killed five boys, apparently adolescents. A bloody crime scene photo suggests that Debrais used some sharp weapon to kill them. It is unknown if Elle interviewed Debrais after the hostage situation she was caught up in ended.
The Montana Strangler
One of Morgan's earliest cases he worked together with Gideon, the Montana Strangler (so named in this wiki) targeted girls. The case brought about a great deal of nightmares for Morgan, who felt like he had been responsible for a later murder as he had told the police that he could make a profile if he had more information, i.e. another victim.
Abductor of Deborah Addison
A case Gideon worked on in 1985. While walking home from school, thirteen-year-old Deborah Louise Addison was abducted by a predator. The BAU was able to successfully profile and locate the unsub and saved Deborah before any harm could come to her.
Unnamed sex offender
An unnamed sex offender who turns up in Garcia's search. According to her, his rap sheet was so long that he should still be in prison.
An employee of Hichcock Pharmaceuticals, who became romantically involved with poisoner Edward Hill and assisted him in a mass poisoning that affected eight people. To eliminate loose ends, he later murdered her with a toxic combination of several drugs and poisons.
The Boise Child Killer
The Boise Child Killer (real name unspecified) was an apparently prolific serial killer in Boise, Idaho, who targeted children. He was captured through a profile given by Max Ryan.
Unnamed bomber case
One of Gideon's earliest cases, supervised by Max Ryan. Presumably as a form of hazing, Ryan and the other investigators planted a list of the FBI Director's whereabouts over the next 48 hours among the bomber's things for Gideon to find. When he did, he rushed up 25 flights of stairs and interrupted a meeting between the Director and the Attorney General in an attempt to save him.
Unnamed mass murderer
A man who killed an unspecified number of people and was later arrested and imprisoned. He became cellmates with Jackson Cally at some point during Cally's own imprisonment. Cally manipulated the man into killing an inmate who threatened the former. It is assumed that the man was charged and tried for this new murder.
The Boys in Iowa
The Boys in Iowa was one of the first cases Hotch and Gideon worked together. Two children had been murdered and the authorities had no leads. Gideon and Hotch delivered the profile, which led them to a local 4H leader. As they moved in to arrest him, he held them at gunpoint and a brief standoff ensued, but they were able to talk him down and make an arrest. When the case went to court, however, the man’s wife gave him a false alibi for the murders, leading to him being acquitted and released. In the end, he was finally incarcerated after killing a third child.
At least one person who attempted to rob Albert and Gail Doyle, the parents of future serial killer Marvin Doyle, but wound up fatally shooting them in the process. The murders went on to be one of the triggers for Marvin's serial killing.
Will Sykes's mugger
A man who mugged future cop killer Will Sykes. Apparently, the mugging was so severe, Sykes had to be in intensive care for two days. The mugging would motivate Sykes to want to copy Marvin Doyle's crimes.
Olivia Hopkins' captors
A group of men who took CIA Agent Olivia Hopkins hostage during one of her field operations in Europe. During this time, they sexually assaulted her. She was eventually rescued, though it is unknown what happened to her captors.