In The Red Tattoo, he is introduced as the officer who investigated Bob Kirkland's shooting. Although the culprit was Reede Smith, his report said it was the transportation Officer who killed him because he refused to listen to his verbal warnings. Although Cordero knew that Reede Smith was the killer, his involvement with the cover-up wasn't revealed until his next appearance.
In The Great Red Dragon, he is revealed to be a member of the Blake Association. His main roles in this episode are attempting to kill Reede Smith, and helping Gale Bertram escape from the police. He fails at one, and succeeds at the other. He is interrupted twice by the CBI while trying to kill Smith, but he initially escapes. Although, he did help Bertram escape from the police after being accused of being Red John.
In Red John, he kills a police officer while trying to protect Gale Bertram. When Jane goes to meet Bertram at the cathedral, he is stopped by Cordero. Cordero pats him down for weapons. He finds a gun, but fails to find a pigeon. When in the cathedral, he witnesses Bertram defending himself of not being Red John. When Bertram asks him to execute Jane, Cordero, under the real Red John's orders, shoots Gale Bertram in the chest, killing him. Red John, revealed to be Thomas McAllister, thanks and asks Cordero to exit the cathedral while he speaks with Jane. When Jane shoots McAllister in the stomach, Cordero returns, only to be shot twice in the chest by Jane. It is presumed that Cordero didn't survive his wounds, as he is never mentioned again, however he is shown alive.
- Unnamed police officer (Shot to death after drawing his gun on Bertram)
- Gale Bertram (Shot to death on Red John's orders)
- It is hinted in Red John (episode) that he would not only be Red John's main hitman, but also the number 2 in the Blake Association hierarchy