Police in Brazil have arrested two suspects in the killing of Rio de Janeiro councilwoman Marielle Franco and her driver.

The brazen assassination of the two on March 14 last year led to massive protests and widespread anger in Latin America's largest nation.

A police spokesman told The Associated Press that two men were taken into custody early Tuesday. Per agency protocol, the spokesman asked that his name not be used.

The two men arrested were former police officers, according to the police spokesman. One allegedly shot Franco and the other drove a car involved in the shooting.

Franco, who was black and a lesbian, had been a frequent critic of police violence, particularly in poor neighborhoods called favelas.

Marches are planned for Thursday, the year anniversary of the death.