Friday morning's testimony began with state prosecutors calling Erika Patterson to testify.Patterson says her history with Brooks goes back 15 years, and they have a child together.On Nov. 21, 2021, Patterson told jurors she was arguing with Brooks in his car near Frame Park in Waukesha when she claims Brooks struck her in the face with a "closed fist.""I cried, and then I just jumped out of the car and then going towards down the hill. That's when he was following me," Patterson said.Patterson says some friends came to help her and said Brooks drove off in the red SUV.Prosecutors asked Patterson to describe Brooks' demeanor."Besides the fact that he was arguing the whole time and he hit me, he was just mad. He just left very angry," Patterson said.When it was Brooks' turn to cross examine his ex-girlfriend, he first wished her a happy birthday."Good morning, and happy birthday," Brooks said.Brooks continued to question Patterson about why she agreed to meet him at Frame Park if they were arguing."Because I just wanted to, we have a 15-year-old together," Patterson said.Patterson, at times, seemed frustrated with Brooks' line of questioning, and after asking the same questions multiple times, Judge Jennifer Dorow shut it down."I'm stopping this cross-examination. You've asked the same question, multiple questions multiple times," Dorow said.Brooks did not have to be removed from the main courtroom on Friday for interrupting the judge. He was overruled on a number of objections, even telling the judge at one point he was emotional. Jurors also watched, for the first time, dash camera video from Waukesha police Officer Jeremy Phillips. Phillips responded to Frame Park for a report of a fight with a subject who has a knife. When on scene he had just started to interview Patterson when he got word over the radio that multiple people were hit on nearby Main Street. Phillips described the scene as chaos and carnage."There were parents screaming at me to help their kids. I did what basic measures that I could take as far as emergency lifesaving goes. I checked pulses. I asked them to squeeze my finger, ask them what they can move. The two or three I talked to could still move," Phillips said.The officer helped several members of the Waukesha South Band, testifying that one member told him what happened."She said, a red SUV sped through the parade and did this. She didn't say anything more than that. I said, Oh, OK. I was like, stay with your family. Stay with your parents," Phillips said.