PARIS — When French police raided the home of Amedy Coulibaly, a suspected Islamic extremist, in May 2010, they found his computer crammed with religious texts, holiday pictures of himself with a veiled female companion and photographs of a “pedo-pornographic character,” according to an official record of the search. They also found 240 gun cartridges for a Kalashnikov automatic rifle.

Charged with involvement in a plot to spring a convicted Franco-Algerian terrorist from jail, Mr. Coulibaly denied any knowledge of any such a plan: “I’m the village idiot in all this. I know nothing about anything,” he told French investigators. “I have done stupid things, but frankly there are limits.”

Whatever limits he may have had in 2010, however, disappeared by this past week, when Mr. Coulibaly, 32, and his 26-year-old companion, Hayat Boumeddiene, became prime suspects in a bloody rampage, the worst terrorist actions to hit France since the 1954-62 Algerian War.

Suspected, along with Ms. Boumeddiene, of involvement in the roadside killing on Thursday of a trainee police officer in southern Paris, Mr. Coulibaly — armed with a Kalashnikov rifle and an automatic pistol — on Friday seized a kosher supermarket in the east of the city. There, authorities say, he killed four hostages before dying himself when elite police units stormed the building.