Nabila Ramdani is a Paris-born freelance journalist and academic of Algerian descent.

Republican values of liberté, egalité, fraternité will be all but forgotten when thousands of Parisians recall the most murderous episode in the French capital's postwar history tomorrow. Commemorations are planned for the 50th anniversary of the French-Algerian massacre, when up to 200 peaceful protesters were slaughtered in cold blood around iconic national monuments, including the Eiffel Tower and Notre Dame Cathedral.

The most memorable – and vicious – atrocities saw policemen herding panicking crowds on to Paris's bridges, where many were tossed into the Seine. Normally a romantic symbol of the most popular tourist city in the world, the river became a watery morgue for scores of victims, whose lifeless bodies were washing up for weeks afterwards.

Others died in police stations, or in nearby woods, where their mutilated bodies testified to truncheon and rifle-butt injuries. The officers had been incensed by an illegal protest by 30,000 men, women and children organised by the National Liberation Front (FLN) – the main Algerian nationalist group in their country's war of independence with France.

Fifty years will seem like a long time to many of the young French Algerians who mark the anniversary today, but in many ways it seems very recent. Maurice Papon, the Paris police chief who instigated the killings, only died four years ago, aged 96; and some of his unrepentant and unpunished henchmen still remain at large...