This will be my only post on this subject.
I offer my condolences to all affected by this tragedy. I have grandchildren (3, 1, 1) and although my children are adults now I can barely imagine the grief.
I was a cop for 30 years. Never had a gun, wouldn't want one. Was at the wrong end of one a couple of times.
I have no idea what the solution to all this is, or if there is one now - maybe it's gone too far.
Some years ago I was in the US working on a case. I worked with two FBI guys. One never carried his gun but it was to hand if needed. The other (much younger) carried his all the time, including to church. One guy we dealt with had 147 firearms and he and his wife slept with loaded 9mm automatics under their pillows - in a very rural, almost zero-crime area. When this guy and his wife came to the UK to give evidence we had to convince them NOT to wear bullet-proof vests when they gave evidence (he insisted on wearing his under his clothes).
When my colleague and I were off-duty on our visit, we wandered around (as you do) and ended up in some fairly unsavoury places. Unarmed, not hiding that we were police, 'innocents abroad'. We had some interesting encounters but never had a major problem, maybe because we were used to talking to people rather than getting into pissing contests.
The UK is not, of course, a paradise and we have many problems here. But I offer my sympathies to my US friends because I don't think you're living in the land of the free - I wonder if you're living in the land of fear.
No offence intended.