Rio de Janeiro (AFP) - Bullet casings at the scene of the apparent assassination of a black civil rights leader and city councilor in Rio de Janeiro once belonged to Brazil's federal police, Globo news reported Friday.
The casings were for the nine-millimeter bullets used to kill Marielle Franco, 38, late Wednesday in the center of Rio. Her driver was also killed and an aide lightly injured in a brazen attack that sparked protests by thousands in Rio and Sao Paulo on Thursday.
According to Globo television's report, the ammunition had been purchased by federal police in the capital Brasilia in 2006.
Ammunition from the same lot, according to the report, was used during a Sao Paulo massacre of 17 people in August 2015. Three police officers are among those convicted of the mass murders.
Police are investigating whether the killing of Franco -- a police critic -- was a targeted hit.
She was elected to Rio's city council with the leftist PSOL party in 2016 and was an outspoken supporter of poor black inhabitants of favelas, frequently accusing the police of carrying out extrajudicial killings.
Franco stood out in Rio's male and white-dominated political scene, and also spoke out against the decision last month to put the military in charge of Rio's security.
Federal police said in a statement that they were investigating "the origin of the ammunition and the circumstances of the casings found at the scene of the crime."