|Significant other(s):||Valeria Crosley (formerly)|
|Hair color:||Dirty blond|
|Aliases:|| Greatest Thief That Ever Lived|
Royston Cornwallace Staley
|First appearance:||Extradition: British Columbia|
|Last appearance:||Lock, Stock, Some Smoking Barrels and Burton Guster's Goblet of Fire|
Extradition: British ColumbiaEdit
Shawn discovers in "Extradition: British Columbia" that Desperaux never gets caught because owners in financial distress make it possible for him to steal the items so that they may collect the insurance money. Making what he does more insurance fraud than anything else.
Extradition II: The Actual Extradition PartEdit
In "Extradition II: The Actual Extradition Part" Shawn and Gus return to Vancouver on the request and tab of Despereaux just before he is to be extradited by Lassiter. Despereaux wants to prove he is the "Greatest Thief That Ever Lived" and escapes from prison to commit an elaborate art theft from the Canadian crown prosecutor's house. But after the job is done he is framed for the death of the crown prosecutor. Shawn eventually discovers it was Despereaux's girlfriend who set him up.
Indiana Shawn and the Temple of the Kinda Crappy, Rusty Old DaggerEdit
In "Indiana Shawn and the Temple of the Kinda Crappy, Rusty Old Dagger", a valuable shipment of artifacts is stolen from a museum. Shawn needs "professional" help in getting them back. So he calls in Pierre to help them catch the thief who stole the shipment. The thief was actually after a dagger that opens the door to a secret stash of paintings. Over the course of the investigation, Despereaux is forced to fake his own death in order to avoid prison. Then, along with Shawn and Gus, he uncovers the art, revealing many seemingly worthless paintings. He later steals one of these and removes the paint, revealing a Rembrandt underneath. He is now believed by the SBPD to be deceased, though we know this is false, finally making Pierre Despereaux the world class thief that both he and Shawn have always envisioned.
Lock, Stock, Some Smoking Barrels and Burton Guster's Goblet of FireEdit
In "Lock, Stock, Some Smoking Barrels and Burton Guster's Goblet of Fire", he called Shawn and Gus to England so Shawn can pose as a getaway driver. Despereaux was posing as Interpol agent Royston Staley, although Gus is still skeptical. Shawn and Gus found out that Royston Staley, nor the alleged agent who hired him existed, so they began to suspect and investigate him. When they got called to do the heist, the picked up Despereaux to help them do the heist, however he claimed to be undercover. When Shawn and Gus were tied up by the other robbers, Despereaux snuck away with the jewels, but saved Shawn and Gus and Interpol arrived. However, a royal was killed, so Despereaux was suspended by the man who hired him and cleared out his things. Shawn and Gus had accepted that Despereaux was an undercover agent, except they later saw the man who was supposed to be Despereaux's superior on the streets as a beggar, meaning he had been a fake, and Despereaux had infiltrated Interpol.
- In his last appearance it is hinted that he may also be a spy working with Interpol.