What I'm trying to argue is that you cannot make a one-size-fits-all solution to incidents such as the one we are discussing when each one takes place in radically different social environments and cultures. Britain and the US are culturally divided by much, much more than Churchil's quip about a common language. One of the most fundamental differences is in relation to the degree of socialisation vs. individualisation of each society. I'd explain that by suggesting that British people are at root trusting of authority and hence constantly disappointed by the behaviour of their political elites. US society seems to approach authority with a fundamental suspicion of governmental authority, and might generally have their suspicions reinforced, occasionally proved wrong.
The British as a whole (and countless opinion polls and consultations with police officers reveal the same) DO NOT WANT an armed population or police force, not because they want to behave as sheep, as per your link article, but because if you limit access to firearms to all, you limit access to sheep, sheepdogs AND wolves. If you make gun ownership and the procurement of weapons more difficult, vigilance of the illegal trade becomes tighter too; you cannot then mistake an illicit trade transaction for a legitimate one if there are
no legitimate ones.
In fear of repeating myself, you cannot turn a non-gun-owning society into a gun-owning society in the hope that the small number of shocking incidents such as yesterday's, the like of which happen on average about once a decade, might possibly have been prevented had someone, somewhere had a gun to hand.
I'm making no recommendations about what the attitude of Americans should be towards gun ownership as yours is clearly not a society I'm too familiar with. I am saying that any move towards turning British society from a gun-rejecting into a gun-accepting culutre would be a very, very bad transformation and would lead to a situation where the gun death rate, which currently stands at less than a third of that of the US, would supersede it very quickly because of the ignorance and unfamiliarity of using, storing and maintaining weapons and through ignorance of the dangers and consequences of gun ownership and misuse - a practice and tradition that is entirely alien to the vast majority of Britons.