Officials say a Brazilian man barged into a judge's office, pinned her to the ground, doused her with a flammable liquid and threatened to set her on fire if she didn't declare he was innocent of beating his wife.
Police say Alfredo Jose dos Santos attacked Judge Tatiane Moreira Lima, who handles domestic violence cases.
They say he poured a flammable liquid over her and threatened to spark a cigarette lighter. They didn't specify what the liquid was.
In a video shot by a police officer, Santos is seen forcing Lima to say "he's innocent."
After about 20 minutes on Wednesday, police rushed Santos and released the judge, who suffered minor bruises. He remained in custody on Thursday.