Two men have been arrested over the murder of Marielle Franco, an outspoken black councillor in the Brazilian city of Rio de Janeiro.
The arrests come almost a year after Ms Franco and her driver were shot dead, an incident which caused mass protests.
Ms Franco had been highly critical of the deployment of federal security forces to Rio's poor neighbourhoods.
Police said both suspects were former members of the military police force.
Ms Franco was returning from an event encouraging black women's empowerment in central Rio on 14 March 2018 when a car drew alongside hers and nine shots rang out.
She was shot four times in the head, and three bullets hit her driver, Anderson Gomes. Ms Franco's press officer, who was sitting in the back seat of the car, was injured.
One of the suspects arrested on Tuesday is accused of being the gunman, the other of being the driver.
The killing shocked Brazilians, who took to the streets of Rio de Janeiro and other cities en masse in protest.
With the anniversary of her murder approaching, there was also criticism of the fact that no-one had been brought to justice for her murder.
Only last week, the Mangueira samba school paid tribute to Ms Franco during their parade at Rio's Carnival, a sign of the councillor's enduring influence.
Ms Franco, who grew up in a poor neighbourhood of Rio, had been a critical voice on the commission overseeing the deployment of federal security forces into the city's favelas.
The day before she was shot dead, she posted a tweet critical of the killing in the Manguinhos favela of a 23-year-old man, which his family blamed on the military police.
"Another killing of a young man which could end up on the PM [military police] tally. Matheus Melo was leaving church. How many more will have to die before this war ends?" she asked.
End of Twitter post by @mariellefranco
Investigators say her killing was meticulously planned and carried out with unusual precision, which led them to believe her killers were highly trained.