Thats kind of a loaded question and a very tough one to answer.
I dont believe they should be chasing ANYONE with a vehicle in the city. Its just not safe at all and more times than not, an innocent person winds up getting fucked up. Now you might counter, what if someone just killed your Wife, kid or family member etc. Fuck yeah, I'd want them to chase them, because of the heat of the moment and I would be insanely pissed if they didnt. I guess this is one of those, "your damned if you do and your damned if you dont"