Who could have done this stabbing on the Paris Metro?

I'll give you three guesses and the first two don't count: "Illegal African migrant with deportation order suspected in Paris Metro mass stabbing."

He was imprisoned last year for - wait for it! - sexual assault.  But then he was released in July with a deportation order and - you'll never believe it! - he didn't leave. 

The tolerant French are getting sick of this merde:

Unsurprisingly, there is widespread appetite in France for a reform of the status quo. A survey taken earlier this year found that nearly nine in ten French voters would support a system in which those issued with deportation orders were remanded in jail until they are removed from the country.

That is a step in the right direction.