Brazilian police are trying to determine whether the three doctors who were shot dead by gunmen in a Rio de Janeiro bar were “accidentally killed” as clashes between drug traffickers and civil guards rage.

Rio de Janeiro’s police chief, Renato Torres, expressed his belief on Friday that the gunmen belonged to a drug-trafficking gang and that they mistook one of the three doctors for a member of the militia.

Militias, made up of former – or even active, sworn – police officers, are extorting residents of the neighborhoods they control in Rio. As part of their relentless struggle to control more and more territory, they clash with gangs. Among the most powerful gangs are the Comando Vermelho (Red Commandos) who control the drug trade.

The three doctors were in Rio de Janeiro to attend an orthopedic conference. On the night of Wednesday to Thursday they went to a bar in the upscale neighborhood of Baja da Tizuca (west). Security camera video shows the doctors, sitting around a table, being surprised by three men dressed in black who get out of a car and start shooting at them.

A few hours later, four men were found dead, including one of the main suspects in the massacre, police director Renato Torres said.

The authorities estimate that the executioners paid with their lives for the “mistake” they made to kill the three doctors, at the behest of the cartel leadership. “We believe that they (the drug traffickers) themselves were angered by the act of some of their members and sentenced them (to death),” said Rio’s governor, Claudio Castro. “This is a mafia, a very dangerous criminal organization,” he added.

After the murder of the three doctors, suspicions of political motives were raised, as one of the victims was the brother of MP Samia Bofim, a member of the left-wing party “Socialism and Freedom” (PSOL).

Black activist and Rio city councilor Mariele Franco, who was murdered in March 2018, was also a member of the same party. Five years later, the moral perpetrators of her murder have not been identified.