One of his best friends noticed the stark changes over the past two years.
"He grew a beard and stopped saying hello," says Radaa Abdullah of Mohammed Larossi, who died as a suicide bomber in a massive attack on Casablanca last Friday that killed 41 people. "When he did [greet you], it was only to talk about Afghanistan and those he called great holy warriors."
Mr. Larossi - like his colleagues in Assirat Al Moustakim, or the Righteous Path - had embraced an austere form of Islam that took law and judgment into its own hands. The devout young men worked on the premise that anyone not following the tenets of Islam should be punished in public - even waiting up at night to catch beer drinkers and womanizers walking home.
"Moustikam members would take you into an alley and beat you shouting, 'Allahu Akhbar [God is great]!" says Said Shuke, who was assaulted himself one night on the way home from the Cafe Noir, a once-jovial establishment near the Thomasville slum.
Yet the beatings did not overly alarm many residents of this tiny slum, formerly the estate of a French colonialist, Mlle. Thomas. Morocco has flirted with various forms of Islam, some moderate and some extreme, for centuries. Many of last Friday's suicide bombers continued to wear jeans and drink mint tea with friends who remained oblivious to their intentions.
Certainly the young men of Thomasville were not acting strangely enough for anyone to envision that eight of them from this and a nearby shantytown would go on a suicidal rampage. It wasn't until the Righteous Path's own jihad, or struggle,crossed paths with a larger international one commanded by Osama bin Laden that mass slaughter became possible, say Moroccan officials, Western diplomats, and local residents.
Moroccan investigators are now hunting for two of their countrymen who trained in Afghanistan and later took up residence in Belgium and the Netherlands. In a related development, a senior Saudi official said Wednesday that security officials had captured three Moroccans who, he said, appeared poised to try to hijack an airplane for a suicide mission. Saudi officials, who later gave conflicting accounts of the arrest, said the Moroccans were believed to be members of Al Qaeda. The Moroccans were not immediately linked to last week's suicide bombings in Riyadh though possible involvement was being scrutinized.
Mohammed Naji, a Thomasville resident, said he believed the local men were pushed from the outside "by bigger operatives who had more experience with international terror."
"I don't think they knew what they were stepping into when they strapped on those bombs last Friday night," he says. Indeed, early results of an investigation show the bombers were not highly trained - an indication of how easy it is for terror networks to turn disenchanted young men into time-bombs.
The bombing in Casablanca is now a subject of intense study by US, French, Belgian, Spanish, German, and Moroccan investigators. Forensics specialists from the FBI in Washington flew in this week to offer their expertise. Spain's defense minister, Federico Trillo, speaking from Spain's North African enclave of Ceuta this week, said operatives activated detonators on the attackers' vests using mobile phones. The more senior operatives, dialing in from Europe or elsewhere in Morocco, thus managed to set off five nearly simultaneous blasts.
In a sweep of the slums, police found dozens of containers filled with materials used to make plastic explosives, the kind Al Qaeda has experimented with. Quantities were far greater than what was needed in Friday's attacks.
Investigators are also trying to talk to the dead bombers' families. Police have imposed a curfew, allowing them to move from house to house after sundown, making what residents say have been "hundreds" of arrests. Notably, no family member has gone to Ibn Rochd Hospital to claim a bomber's body.
From a distance, Thomasville looks like a rickety tin staircase running down from rows of spacious middle-class apartments. Its metal roofs stand out amid the alleys. There is no running water, but plenty of electricity and many mobile-phone users. At midday, crowds of giggling teenage boys and girls in neat white shirts rush home from school to see parents and prepare for prayers.
Mohammed Hajemi, owner of the Cafe Noir, says Righteous Path members met in different mosques in the area, mostly small, rundown establishments less popular with families than the one grand mosque near his establishment.
"I'm not sure the authorities really understand these people and what their goals are," he says. "To address the situation, the government will need to do more than arrest gangs of young men. They will also have to give people jobs and more opportunities. Many families here have seven kids and the father does not work."
In a Thomasville barbershop, Ahmed, a truck driver, speaks softly about last Friday's mayhem. "We have an expression that 'if you apply enough pressure, you will get an explosion,' " he says before moving on as a plain-clothed policeman slips in for a cut.
Morocco has a wealthy upper class but a median income of just $1,000 per worker. The literacy rate hovers at 50 percent, and is lowest in rural areas.
Western diplomats, while praising King Mohammed VI for moving toward a more inclusive political system - and working with Islamic parties - fear Morocco may stand at a crossroads between democracy and theocracy.
They worry about a scenario in which Islamic parties, currently on the rise, win an election and then have the results stolen from them - as occurred in the early 1990s in Algeria before that nation tumbled into civil strife that has left more than 60,000 dead. "You have to wonder if the king is unleashing something he won't be able to get back into the bottle," says one Western analyst.
Like Egypt's Anwar Sadat, Mohammed VI's father, Hassan II, built up Islamic parties here in the 1970s at the expense of the left and other secular groups. Sadat's error led to his own assassination in 1981. But the Moroccan monarchy managed to keep a lid on most forms of extremism until last Friday. Now, the government has the delicate task of fighting religious-inspired terror and moving ahead with plans to allow Islamists to run more candidates in local elections this September.
Imam Lahbil Arbe, who preaches tolerance towards foreigners and other creeds at Thomasville's largest mosque, says the bombers were an aberration. But as he speaks, a young man passes by and shouts "Righteous Path!" before laughing and disappearing into the maze of shanties. It isn't clear if he is a follower - or simply in the mood to offend the aging religious leader.