Your 911 calls don't display a caller ID?
The prankster was almost 1500 miles away....
I actually have some expertise on this.
I installed and tested E-911 systems in thirteen Texas towns, Copperas Cove, Lampasas, Kempner, Fort Hood, Killeen, Harker Heights, Burnet, Bertram, Liberty Hill, Georgetown, Florence, Belton and Temple.
An E-911 system differs from standard POTS (plain old telephone service) 911 systems in that the landline and cellular networks generally can be counted on to pass along important metadata such as location, phone numbers, etc. In the case of cellular, the location might only be the nearest cell tower or it might pinpoint the caller's physical address depending on how new the POTS 911 system actually is. The response center is known as a Public Safety Answering Point.
Not all PSAPs have the cellular and POTS systems fully integrated.
E-911 systems also tie in to local exchange carriers, or LEC's, at the PSAP but if the call originates from a Voice over Internet Protocol service (VoIP) such as Skype, or any of dozens of other "chat + phone" integrated services, the version of Session Initiated Protocol (SIP) that the VoIP program uses may or may not provide sufficient details.
Sometimes a PSAP dispatcher will be greeted with nothing more than "OUT OF AREA" on the screen when a 911 call comes in.
Recent changes to FCC laws now might require VoIP and SIP itself to be much more verbose, but that does not mean that the PSAP centers are being updated everywhere...some centers are lagging behind due to budget cuts or other issues, so even if such a call comes in with more detailed info, the PSAP dispatcher still might not be able to see it in real time, or they might only discover the E-911 VoIP caller's location AFTER the FACT, when they dig deeper.
There is also the issue of ALI FAILURE (Automatic Lookup Failure) where the information is supposed to be displayed in real time but may fail to do so.
There's much more to this, too much to go into in detail here but the point I am making is that the Enhanced 911 system is far from perfect, can be spoofed or exploited, and there is not always all that much that municipalities or the FCC can do about it short of abolishing all nomadic VoIP services altogether permanently and forcing all VoIP customers back onto POTS and cellular systems.
Good luck.