Compare to when arsonists burned down 61 West Philadelphia homes, killing 5 children. That's a threat to public safety, but the arsonists were never charged, because the arsonists were police. That's a threat to public safety.
Compare to systemic racism, repeated kidnapping and harassment, and over and over again, cops straight-up murdering black people. That's a threat to public safety.
Let's be clear here, you aren't concerned about justice or removing threats to public safety if your biggest concern here is the torching of two unoccupied police cars.