The main suspect in Friday's knife attack in Turku was a threatening presence at Turku's Pansio reception centre, and the centre's management warned him about his behaviour more than once.
That's the picture emerging from interviews Yle conducted with several people who knew the suspect at the asylum seekers' centre.
Their accounts are consistent with each other, but Yle is not reporting their nationalities, genders or the number of sources in order to protect their identities.
False identity, wrong age
The man presenting himself as Abderrahman Mechkah came to Pansio Reception Centre in December 2016. On arrival in Finland he had told the authorities he was 17 years old, and spent his first six months in a centre for underage asylum seekers.
When he reached adulthood (according to his declared date of birth), he was transferred to the adult unit. There people noticed his radical views and behaviour. He spoke of Finns as infidels and asked for tips on how to join Isis.
According to Yle's sources, his real name is not Abderrahman Mechkah. He boasted of giving Finnish authorities the wrong name and age, but his real name and date of birth remain a mystery. Yle's sources estimate that he is aged over 20.
German media reported on Tuesday that Mechkah had used several identities in Germany, where he lived before he came to Finland. While there, he was suspected of several assaults. Two of the other suspects remanded on Tuesday were also known to German police, suspected of involvement in robbery and theft.
Pumped iron, made death threats
In the reception centre, it was apparent that Mechkah held radical opinions. He listened to radical sermons on his mobile phone - as well as hip-hop.
One source said that Mechkah claimed he had killed someone in Morocco, and when riled, he had a habit of making death threats in Finland too.
He sometimes used the Arabic word 'kuffar', or 'infidel' to refer to Finns. He went to the gym every day and used protein supplements to increase muscle mass and occasionally he went to the swimming hall. Yle's sources suggest that he was in good shape, and had a muscular build.
His daily routine also included Finnish lessons. People who know him do not consider him to be mentally ill or to have a psychiatric disorder—most say he was clearly intelligent but that his behaviour set him apart.
Older Moroccan man comes to visit
Mechkah spent much of his time with a group of around five other Moroccan men. In that group are the same men police suspect of participation in the Turku attack. According to Yle sources, the group smoked cannabis together. One of the Moroccan men detained over the weekend has been released, while an international warrant remains out for a sixth man.
According to Yle's sources, some of the group lived in the same reception centre, and some of them lived elsewhere. Yle's sources guess that the youngest members of the group lied about their age, as they suspect Mechkah did.
An older Moroccan man who lived abroad was observed with the same group last winter. He drove a white van and seemed to have money—and an influence on younger members of the group.
Several people observed that Mechkah seemed to have expensive clothes and items that he could not have bought with the small per diem sums he received from the reception centre. Some sources suggest that the Moroccan group may have been dealing drugs and stole property.
Those who know Mechkah believe that other members of the group had helped deepen his radicalisation, and were sure that he did not plan the attacks by himself.
Isis sympathies reported
Some Yle sources report that they warned managers at the reception centre about Mechkah's radical views for the first time in January 2017. The tip-offs concerned his interest in Isis, threatening behaviour and use of drugs.
Managers apparently promised to pass on that information to the police and to pay closer attention to Mechkah within the centre—but those who had tipped them off said they didn't notice any special measures being taken.
The assistant director of the centre, Heimo Nurmi, said that the tip-off was unusual.
"That kind of message doesn't come every day, and we forwarded it to police," said Nurmi. "I don't believe it has been downplayed or misunderstood. When concerns are raised, they are taken seriously."
Nurmi says he has no recollection of any promises to place Mechkah under special surveillance.
"It's the police's job to investigate if there is something to investigate," said Nurmi.
At the start of the summer Mechkah was transferred to dormitory accommodation in the main building of the centre together with another 18-year-old Moroccan.
On Monday Finnish Security Intelligence Service (Supo) confirmed that they had received a tip-off about the young man's radicalisation at the beginning of the year. They did not react to the information then because there was no information about a concrete plan for an attack.
Supo says that they receive a large number of similar tip-offs.
When those who knew the man realised that the perpetrator of the stabbings was Mechkah, they were shocked and disappointed with the authorities who had failed to act on their warnings.
After the attack, some of those interviewed by Yle have talked or tried to talk to the police. They believe that the police don't fully trust them, but instead regard them with some suspicion.