You mean like the video his racist rant in the CV Pharmacy that was disallowed? Where he said he wished he could shoot people? Or the teenage girl he beat up? Or his meetings and weekends with the Proud Boys. All of which the judge disallowed as "prejudicial".
I looked at Rosenbaum's record - which you have no way of proving is real. He was 36 when he died. The two cases of "sexual conduct with a minor" that Rosenbaum was charged for happened in 2002 - 19 years before he was killed. Rosenbaum was 17 when he was charged, so he was a minor himself when he was charged. Yes, he was real problem child there for a while, but he turned his life for more than 4 years before he died.
Furthermore, his last charge was in 2014 and that was for interfering with his monitoring device. So this is a guy who hasn't harmed anyone or broken the law since he was 17 - nearly 20 years ago. But it's OK that Kyle Rittenhouse killed him because at one time, he was up on charges, and he was a real jerk when he was younger.