When I lived in Chicago in late 70s, I was out cruising one night.
I spot a salt and pepper team (a white guy and a black guy) looking to steal cars at night.
I called in on CB to a base station and they sent the cops out. I gave them a description of the van they were in, but I was not close enough to see the tags.
Not sure if they ever caught them. ;)
"When bad men combine, the good must associate; else they will fall, one by one." Edmund Burke