Rio de Janeiro, Aug 13 (IANS/EFE): A Brazilian judge who received death threats after imposing harsh sentences on vigilantes was slain Friday in suburban Rio de Janeiro, police said.

Patricia Lourival Acioli, who presided over a criminal court in the municipality of Sao Gonzalo, was shot by four assailants when she pulled up to her home in the early hours.

The attackers fired at least 16 shots at the judge as she sat in her vehicle waiting for the garage door to open, police told the media.

Acioli, a 47-year-old mother of three, heard murder cases and was known for her tough stance toward members of "extermination groups" that kill petty criminals, beggars and homeless people in Rio suburbs.

The death squads are led by corrupt police officers, often in league with organized-crime elements. Among the people Acioli convicted of vigilante murders were militiamen and criminals engaged in fuel and transportation rackets.

Relatives of the judge said police withdrew her armed escorts several months ago despite persistent death threats.