A commander in Rio de Janeiro's Military Police has been arrested on suspicion of masterminding the murder of Judge Patricia Acioli, who was gunned down in August.
Lieutenant Colonel Claudio Luiz de Oliveira has been in the Military Police for 26 years, according to a report in O Globo. At the time of the judge's murder, Oliveira commanded the 7th Battalion which operated in São Goncalo, the Rio suburb where Acioli worked.
He was later transferred to command a battalion which operated in another part of the city, but was removed from this post following his arrest in the early hours of Tuesday morning.
The magistrate who ordered Oliveria's detention has been given extra security, according to the authorities. He also ordered the arrest of five members of the São Goncalo battalion.
Three other officers from the battalion had already been arrested over the killing. They were among a group that had been accused of covering up their murder of an 18-year-old in June, claiming that they shot the youth while he was resisting arrest.
Acioli was known for her hard line against police involved in this type of killing, which is common in Rio, and the officers are suspected of having planned her murder in order to avoid being sent to prison.
Following Acioli's death, Rio authorities have cracked down on militia groups in São Goncalo, which have close ties with death squads made up of police officers, and are funded in part through the illicit provision of public services, including transport.