MADISON, Wis. >> A Wisconsin man defending himself against homicide charges for allegedly plowing his SUV through a Christmas parade stripped off his shirt, sat with his back to the camera and stuck a sign he’d been given to signal objections down his pants Thursday before opening statements began in his trial.

Prosecutors allege Darrell Brooks, 40, killed six people and injured scores of others on Nov. 21 in the Milwaukee suburb of Waukesha. Police said he turned into the parade after fleeing a domestic disturbance, though officers were not pursuing him at the time. The 76 charges he faces include six counts of first-degree intentional homicide. Each of those counts carries a mandatory life sentence.

Brooks has been acting as his own attorney since last week, when he demanded Judge Jennifer Dorow dismiss his public defenders. His trial began Monday with jury selection. Brooks repeatedly interrupted Dorow before prospective jurors were brought in, leading the judge to move him to another courtroom where he could watch via video and speak when she activated his microphone.

Thursday was the first day of testimony. Brooks began the day by interrupting Dorow at least a dozen times before jurors were brought into the courtroom. The judge had bailiffs take Brooks to the alternate courtroom. Once there, he took off his jail uniform shirt and sat on the defense table with his back to the camera. He could be seen gesturing and jabbing the table with his finger.

He was given a sign to hold up to the camera to signal objections, which he stuck down the front of his pants. He also claimed he needed medical help for a cut on his finger. Dorow said there was no blood and he would have to wait until the lunch break. After that break, he appeared to have a bandage on his right pinky.

Brooks at one point pleaded not guilty by reason of mental disease, but withdrew that without explanation and pleaded not guilty. Psychological evaluations before the trial found him competent.

District Attorney Susan Opper told Dorow that she believes Brooks’ antics are aimed at delaying the trial. She said recordings of his calls from jail reveal that he discusses his case with multiple people every day.

“These actions are deliberate and intentional and they have escalated,” Opper said. “He’s attempting to derail these proceedings and delay the inevitable.”

Dorow agreed.

“It’s very clear to this court that everything that he has done as outlined by the state and made evident on the record of these proceedings that it is the sole intent of Mr. Brooks to make a mockery of this process,” Dorow said. “I believe this trial needs to continue and should continue.”

After Dorow called the jurors into the courtroom, Brooks removed his objection sign from his pants and stood behind the table with his eyes closed as Dorow began reading each charge.

Prosecutors finally began their opening statements around mid-afternoon. Assistant District Attorney Zachary Wittchow promised that jurors would see dozens of video clips of the SUV plowing through the parade as well as hear testimony from people who were hit and police officers who tried to stop the vehicle.

“As his body count increased, so did his motive to get away,” Wittchow said. “He didn’t use a gun or knife. He used 3,500 pounds of rubber, steel and glass.”

Wittchow said jurors would hear how Brooks was angry at his ex-girlfriend and sped into the parade after trying to run her down and punching her in the face. According to a criminal complaint, Brooks attacked her because she had refused to bail him out of jail in Milwaukee County on allegations that he tried to run her over earlier that month.

Brooks chose not to make an opening statement, saying he would make one after prosecutors finish their case and it is his turn to present evidence.

Prosecutors then began calling witnesses, including Waukesha Police Sgt. David Wanner, who testified that he was in charge of securing the parade route. He said the SUV “blew by me” onto the route at around 40 mph.