Colonel Mario Sergio Duarte submitted his letter of resignation Wednesday night and the request was accepted by the state’s secretary of public security, José Mariano Beltrame.
The move came two days after a lieutenant colonel, Claudio Oliveira, was arrested and accused of being the man who ordered the killing of Judge Patricia Lourival Acioli.
She was gunned down last month on her doorstep by hooded gunmen in the Rio suburb of Niterói.
Acioli, a 47-year-old mother of three, was known for her hard-line stance against Rio de Janeiro’s criminal gangs and brutal militias, mostly former policemen-turned-drug runners who formed extermination gangs much like the ones seen in Mexico.
Her death came days after she delivered tough sentences against former policemen who turned to crime.
In addition to Oliveira, nine other military policemen have been arrested and accused of direct or indirect involvement in the crime.
The public security secretary said the police commander’s resignation was “voluntary and irrevocable in character.”
A new top commander will be named shortly.
In her 18-year career, Acioli handed down about 60 sentences against policemen and former policemen despite recurring death threats against her, high court criminal judge Manoel Alberto Rebelo dos Santos told reporters last month.
According to investigators, Acioli was on a handwritten death list issued by a leading member of a militia group who was recently arrested in Rio de Janeiro.