I'd suggest police plant some covert agent into the group.
This is getting serious. People shooting at aircraft? That's terrorism.
Don't we have some first-hand experience of doing so in the past?
USA should show the UK police how THEY TREAT such cases.
Joking OK if nobody hurt, but could have been.
That
doesn't realise if he (or she?? to be equal gender opportunities to be violent psycho) actually made the chopper enter some emergency procedure he in theory might see his big yard as the only possible auto/emergency landing spot and thrash his house? Or his family's.