RIO DE JANEIRO/BRASILIA (Reuters) - Two former police officers were arrested on Tuesday on charges they killed a local councilwoman and her driver, Rio de Janeiro prosecutors said, claiming a breakthrough in a crime that sent shock waves through Brazil, a country numbed by rising violence.

Anielle Franco, sister of late activist and councilwoman Marielle Franco, reacts during a news conference in Rio de Janeiro's Public Prosecutor's Office, Brazil March 12, 2019. REUTERS/Ricardo Moraes

The arrests came just days before the first anniversary of the deaths of Marielle Franco, a black, openly gay and progressive councilwoman born in a poor Rio neighborhood, and her driver, Anderson Gomes.

Franco was a vocal critic of Rio police for their often-deadly gang-busting operations in the city’s slums, and took stands against paramilitary militias, made up of current and former police, who are de-facto bosses across wide swaths of the city.

“Two police officers were arrested with a direct and effective participation in the crime,” said Marcus Vinícius Braga, Rio de Janeiro state police secretary. “With these arrests, we are getting close to solving the crime.”

Despite the claims of a breakthrough, some were skeptical. “The case is not yet over,” said one local prosecutor, who asked for anonymity to comment about a case in which he was not involved. “They still need to know the motive of the crime and who ordered it.”

“I don’t like how politicized the case has become ... we need to be very cautious,” the prosecutor added.

The suspects were identified as Ronnie Lessa, a retired military police officer, and Élcio Vieira de Queiroz, a policeman who was expelled from the force.

Lawyers for both men said they did not commit the crime.

Flavio Bolsonaro, a son of the Brazilian president, has been accused of having ties to Rio’s militias while he was a Rio state lawmaker.

Slideshow ( 9 images )

Lessa lives in the same wealthy, beachside community where President Jair Bolsonaro has a home. Investigators said they have no reason to think that any of the Bolsonaros are linked to Franco’s killing.

However, Giniton Lages, head of the Rio police homicide division, confirmed during a news conference that one of President Bolsonaro’s sons had dated a daughter of the suspect Lessa. He did not say which son dated the woman, nor when.

The press team in the president’s office did not immediately respond to requests for comment on details about that relationship.

Additionally, shortly after the suspects were arrested, a photo of Queiroz circulated on social media, wearing a police T-shirt, with his arm around Jair Bolsonaro.

Local news outlets reported the photo was taken from Queiroz’s Facebook profile. Reuters was unable to locate the profile or verify the authenticity of the photo.

Bolsonaro told reporters on Tuesday that he had taken photos with thousands of police officers in the past year as he pursued and won the presidency. He also said that he hoped police discovered if somebody contracted and ordered Franco’s murder.

‘SUMMARILY EXECUTED’

Investigators said Lessa fired the shots that killed Franco and Gomes on March 14, 2018, while Queiroz drove the car that ambushed them.

Simone Sibilio, the lead Rio state prosecutor on the case, said that Lessa and Queiroz were both arrested around 4 a.m. at their homes. She added that Lessa told police he had been tipped off about their raid.

Franco, a human rights and women’s rights activist, was a rising star in the Socialism and Liberty Party. Her press secretary, Fernanda Chaves, who was traveling in the same vehicle, suffered minor injuries.

Thousands took to the streets in protest across Brazil after the killings, which drew international condemnation from rights groups.

According to the document detailing the charges, “it is undisputed that Marielle Francisco da Silva was summarily executed because of the political causes that she defended.”

It remained to be seen if there are any repercussions for the president, who is in the midst of negotiating with Congress on pension reform. Economists say the reform is key to steadying the country’s rickety public finances.

Flavio Bolsonaro, a senator, is being investigated for money laundering during his time as a Rio state lawmaker, and is under pressure to explain how family members of one of the city’s most powerful militia leaders ended up on his legislative payroll at the time.