When Darrell Brooks allegedly rammed his SUV into the Waukesha Christmas Parade—killing six people and injuring dozens—he had two open violent felony cases at Milwaukee County Circuit Court. In one open felony case, Brooks allegedly fired his handgun into a moving car. In the other, he allegedly ran over the mother of his child—with the same car he is accused of using days later in the parade attack. For both charges, Brooks was arrested, locked up, and then let go—first on $500 bail, then $1,000 bail. Milwaukee County is home to Wisconsin’s largest city, Milwaukee, and sits just east of suburban Waukesha. The county operates the state’s busiest criminal courthouse and largest jail compound. The system that enabled Brooks’ releases is dealing with a jury trial backlog caused by months of court shutdowns. It has also been on the forefront of the decade-long movement to reduce prison and jail populations. …