According to the Telegraph article he attacked with a sword the mother of children he had forced to watch videos of beheadings after she filed a complaint about his actions with her children and the police did nothing. Could be exageration, but it could be that some governmental agency was 'running' him before he started killing people. If so, I don't know how likely it is that word would get out. Wouldn't be the first time that law enforcement has been burned by 'informants', but, if so, why did he not make this public as he was going down?

As the Dutch said while fighting the Spanish: "It is not necessary to have hope in order to persevere."