Dear Mr Roe,
I cannot advise you what to do as this is a mater for you. I have not seen the ground, but if in doubt of your experience to take a safe shot in that scenario, my advise is don’t become involved.
Using a silenced firearms is preferable, do not inform the police in case they take a draconian view that this should not happen because it might cause a police call out or complaint etc. The police these days, here and there, operate a ban it culture to avoid what they see as potential problems. What they should be doing is supporting you and advising the public