The fellow jumping over the turnstile who head-butted the cops was wearing headbands?
I haven't seen a photo of the actual suspect,but the papers are reporting him as an illegal immigrant from the Congo, 33 years old. Hardly a "yoot".
As anyone who knows Paris well has observed firsthand, turnstyle jumping is extremely common. It is usually left unchallenged, occasionally, if there is a cop (flic) present, the offender will be stopped, asked for National Identity Card, and given a PV, "proces verbal" the equivalent of a warning ticket. My guess is this offender got violent with the cop and the melee ensued.
The guys in the pictures were bystanders?