Problems with this! The chopper loses visual contact if there are high buildings, etc. This gives the guy time to run into a parking garage of whatever and run on foot.
If he is armed and dangerous - he could cause a lot of harm.
Best to stop him when the police have him in their sight.
I can understand a news chopper losing a visual, as they are directed to keep their distance, but a pursuing PD chopper seldom loses a visual. Besides, even with ground units in close pursuit, the bad guy can still exit his vehicle and run into where ever he pleases if he's armed. Cops generally don't shoot a fleeing felon unless he points his firearm at them. A fleeing suspect with ground units right behind him can walk out of his vehicle and into a building and little can be done, unless he directs a firearm at them. I've seen it happen many times.
Some pursuits become so dangerous, that they have no choice but to back off, and they do this occasionally without air support.