At that point the defense attorney would say: Were you aware that your fellow rioter Shorty Rosenbaum was also a convicted criminal who spent a decade in prison in Arizona, and was a registered sex offender?
Even if the prosecution objects and the judge orders the jury to ignore the question, it would be a devastating line of questioning.
Isn’t it also usually in a probation agreement to “Not associate with felons”? That’s another question that should be asked of Lefty.