Filing a formal complaint against a criminal court judge?

Hello, I was in court today for my friend Melvins trial.. He and six other people are being tried with first degree murder ( please don't judge, this is a really hard time for my family & i ). Anyways, the judge was completely unprofessional, rude, & she kept bringing up the death penalty.. It hasn't even got to the actual like evidence hearings/ trials... My friend melvin is borderline retarded, and he was in psych wards with my sister... My sister dated him for 4 years, & my familys known him for about 8.. He's a nice guy, & theres not really even enough evidence to put him to death.. The judge was being completely innapropriate with the 6 suspects lawyers.. She was acting like they had mentality levels of 3rd graders... I would like to know who I could call & complain to about this? She is extremely biased, and I don't see a fair trial happening.. She's going to pick a tainted jury.. It's ridiculous.. Help me?