checking the location of thee caller. If its not coming from somewhere nowhere near the location of the supposed shooting maybe be a little suspicious. 9-1-1 calls are supposed automatic location identification as part of the E-9-1-1 system.
Swatters are obviously hacking the system by finding ways around that like spoofing numbers. This is a problem that will always exist, though the phone system certainly needs to be be made more reliable. But there's not much the cops themselves can do as a policy change. These laws you cite also force police to accept calls from burner phones with no identity. In one case the swatter called the local police's non-emergency number which doesn't go through the reverse lookup. It's basically social engineering in these cases.
which just brings up the question of why the telecom's cant identify where there own customers are. They obviously know otherwise they could delver service so why cant they pass that information on accurately. why is it even possible to fake the location.