If you are going in the streets in France and if you are arrested, do not forget this mnemotechnic : "AMIS"
A - "Avocat : You have the right to a lawyer, use it, it's important
M - "Médecin" : You also have the right to a doctor, insist to get one AS SOON AS YOU CAN during your arrest and ask them to check your potential wounds AND then go back to the doctor after your arrest if you got violented. It's a safeguard.
I - "Informer" : You have the right to let your close ones know about your situation, use it.
S - "Silence" : Keep silent! Do not talk. Cops will try to make you talk, you have the right to say nothing. Everything you will say can be used against you. Be aware of that. (this last one goes also for the US citizens and most Europeean countries (i think), you have the right to remain silent, always keep your mouth shut and ask for a lawyer).