I understand that the 36 000 thousands tweets that support the killings of Charlie's team of journalists are disturbing and disgusting but rather than immediate prosecution with a very small number of counts to prosecute I wonder whether it is the best choice specially since it will also inevitably lead to prosecute the "moron" style who needs a couple of days and three or four re reading of what he typed to think it through. I guess I would favor a more targeted approach, exclude the above style if no history of tweets that fall in the category and then for all the others make a patient search in files for anything of interest, investigate, pile up the counts and when it looks good, prosecute, strip residency and or citizenship and a must, deport. Once the state has the reputation of doing so, it will reduce the number of tweets falling in that category.
To know if the guy that spoke for 7 hours to the investigators is a new man u'd need to read the testimony. If he is, he has delivered some key elements that help to understand the underlying factors and pattern of the attack. A specialized interrogator over a period of time can tell with the analysis of the motives if there are elements that allow the conclusion a rehab is possible. Where it gets difficult in such a case is the margin error, cause there is one and since the consequences can be devastating a tough job. Reduce the margin means time and is also related to the age and personal history.