You can't have a police officer on every street, ready to respond to any potential attacker before they get a chance to attack anyone. It's not possible. We'd need like a million police officers 🤣 Even if they were on every street, or even just known risky streets, a person can be killed with a mid-size, easily-hidden knife in seconds — even police officers stationed every 500 metres carrying guns and with their heads on a swivel couldn't remove that risk entirely.
The best you can do is have ways to quickly alert the police when people do things like this — like an emergency phone call handling service, or possibly, in a few years, a blanket surveillance system monitored by sophisticated AI, if that's your thing (it's not mine, but I think it'll be possible soon — and we may get it whether we want it or not). Right now, it's phones. Police are alerted to the incident, and appropriate units should be dispatched with appropriate urgency.
I would like there to be well-trained, well-supported officers from a well-funded police force ready to send out, including armed officers, if necessary, in fast-response units covering areas they can respond within rapidly. I'd like the armed officers (including those carrying tasers) to know that their weapons use will be closely monitored and interrogated, but for their training (including all the interpersonal and de-escalation type training) to be rigorous enough for them to feel comfortable that if the worst happens and the weapons are needed, they'll have no trouble carrying out their work within the strictures of the law and police policy, and feeling that they did all they could to minimise harm. And I'd like them to be able to feel confident that if they are required to put that weapons training into practice, and do so in good faith and according to the rules and laws, they will not be unnecessarily penalised or scapegoated, including by punitive-feeling investigations, statements made to the press, or speculative journalists.
We don't seem to have all aspects of this, or, at least, some of them are under significant strain. Many police officers seem to be, if anything, more reluctant to carry guns than members of the public are reluctant to have them carrying them — there's a lot of extra stress and risk involved, and not much reward. Some of that stress and risk is intrinsic to the fact that they'll be put in even more dangerous situations, and may have to harm or kill another human being, but some of it is because they've heard stories of what can happen to firearms officers who've felt that they used their weapons according to their training while dealing with difficult situations, who then have to spend an incredibly long time being routinely investigated in a way that can be very difficult to deal with.
Even if all the issues making officers reluctant to sign up for weapons training were fixed (while retaining safeguards against inappropriate use of weapons, of course), I'm sure there are people in our police force currently who wouldn't have joined if carrying a gun were part and parcel of being a standard everyday police officer. I'm not sure we should force it on them, and if we try, they might just leave, especially if we don't first fix the problems many perceive the system to have. And we're low on police as it is. (We might gain some who join specifically because they get to have a gun, but I'm not sure we want that…)
I know some American police systems, for example, seem pretty broken when it comes to police using guns, because in some areas they appear to be allowed to shoot people with minimal provocation and with near-impunity, but our systems seem to be struggling with (among many other things) the way we've implemented safeguards against excessive gun use, which have made some officers unwilling to train in firearms who would otherwise make good armed officers. Perhaps we need to look at how other countries, maybe especially those who arm more or all of their police officers, manage accountability and safeguards against overreach?
If we can fix these problems so that officers are still accountable for any weapons use but have confidence in the combination of their training and the systems used to monitor their conduct, we might find it easier to recruit enough firearms and taser-trained officers to meet the need for them. We also need to fund the police more broadly, recruiting and training officers to carry out other aspects of policing. And better funding for other services, whose work often devolves onto police by default, is needed. Then even without making all police officers carry guns (or tasers) all the time, dispatchers should always have access to sufficient armed units to send to incidents like the one that promoted this conversation (barring major incidents, but then that can be a problem regardless).
Some people will still die in attacks, because police don't have access to transportation and time travel. But that would happen even with all officers armed and streets crawling with police. I guess you could say that it would be better to be able to send the nearest officer and know that they're armed regardless, and it's possible that that might result in a slightly faster response time to a certain percentage of incidents. But that doesn't seem like it would really be better than a smaller number of intensively-trained, fast-response, armed units who've volunteered for the task and specialise in dangerous situations, with other police officers being more heavily trained in other tasks.
I guess shoving a gun in every police officer's hand whether they like it or not is probably dead cheap tho. And could make a politician very popular with a certain crowd.