Un soir... par hasard
seems one of the 250 twin Jawas(were also known by Chinese people as Shanghai Xingfu 250,by the way)
It actually is a twin 250 Jawa. But I don't know its specific model name.
BSA A7 or A10 The French police actually didn't use Triumph at that time, brotherjack must be right. Look more like an Ariel KH500
Looks like a plunger A10 to me. Don't know about the earlier A10's but the French police did use the later A10s.
Rare and interesting image of a CB in France before the arrival of Honda France, in 1964. Bikes were imported by Psalty, well known parisian garage. Very low sales level, with around 60 sold in 1961, 120 in 1962 and 250 in 1963. CB72 or CB77 Belle trouvaille!
Deux autres vues de la Honda :