How does ATC handle tv coverage of police pursuits in the US?
I know about the operations of police in South Pacific Area so I will answer from that point of view not the USA as is queried.

The Air Traffic Controllers have an agreement set up between the various Police Forces and themselves. This agreement allows them to operate in a covert capacity if required. When they do this special phrases and/or special call signs are used to give them higher priority.

When something like a chase or surveillance is being carried out the police helicopters are usually operating below the control steps. If not they will talking with ATC to obtain a clearance for either to operate in an area or for particular headings. I have seen clearances be issued that say Stay North of Road X Operate Below 1500 AGL.

If Police operations bring them near an airport, the Terminal Area Controllers or Tower Controllers will separate them from the other traffic. In fact this is very safe operations.

As to do with TV helicopters they have to follow the same rules as all the other helicopters. If in controlled airspace obtain a clearance and if not operate VFR under the VFR Rules. The TV choppers would be told to get lost if they were interfering with Police choppers (Yes I have heard it happen).