Most of Montes' targets were around 11 or 12 years of age, and he is known to have committed assaults in Germany, Spain, France, the Netherlands, and the United States.
[5] Montes raped and murdered Caroline Dickinson, a 13-year-old Cornish schoolgirl visiting France with her class, on 18 July 1996, in a youth hostel in the small Breton town of Pleine-Fougères.
Police later discovered that, prior to the murder of Dickinson on the night of 18 July, a man had slipped into a room at another youth hostel in nearby Saint-Lunaire but fled when one of the girls woke and turned the light on.
The murder case went cold until Tommy Ontko, an immigration official at Detroit Airport, picked up an edition of a British newspaper and read the story about the five-year anniversary of the unsolved homicide.
Montes had been arrested in Miami Beach for a lewd and lascivious assault on a female Irish tourist at a youth hostel, as detailed in the "Real Crime" documentary "The Caroline Dickinson Murder".
The crime was similar to the modus operandi in the Dickinson case, with Montes able to enter the girls' room without waking the victim or her roommates.