Guy Martel is a French spree killer who killed seven people and wounded at least five others in several towns and villages in the departments Ille-et-Vilaine and Cotes-du-Nord on June 19, 1985, before he was arrested.

Martel earned a degree in mathematics and chemistry, joined the military and was sent to Costa Rica, where he taught in San José.

He rarely spoke about his time there, but related that he had seen horrible things and had to perform the duties of someone of higher rank who had been killed.

[1] In Dol-de-Bretagne, Martel rarely left his home except to lie in his garden or to play tennis at a local sports hall.

Besides his father; his uncle Charles; and his physician, a Dr Launay, Martel had no visitors and consequently was known as "monsieur tout seul" (Mr. All Alone) throughout the village.

Martel generally was quickly fatigued and complained a lot about noise, especially those made by children, whom he called loud and annoying.

Martel first had a normal conversation with him, but eventually returned to his car, retrieved his rifle and shot Charles three times, wounding him.

When the cook, Mrs. Lozac'h, explained that it was not yet time to eat, he replied that he would come back later ("Je reviendrai tout à l'heure.")

There he entered the office of Launay's colleague, Michel Lhommelet, and killed him with four shots to the back as he was examining a child.

On his way, Martel wounded 34-year-old Daniel Lebreton, who was eating lunch in his truck near Saint-Judoce, and 40-year-old Bernard Prechoux in Saint-Juvat.