It was only a few days ago that I wrote about my fear that a sudden upsurge in public and media concern about violent crime could lead to demand for toughness overwhelming the concept of effectiveness in law and order policy. In a sense, it’s the right’s form of virtue-signalling, prioritising one’s intent – be hard – above actual results, just as parts of the left do for economic policy, prioritising a display of envy above what actually generates the most growth.

The specific policy I mentioned as being at risk was David Gauke’s review of short prison sentences, which currently have a disastrously high reoffending rate. I wrote that: ‘Gauke’s argument is reasoned and reasonable, but it could find itself overwhelmed if a particularly heinous crime, or a particularly bad string of crimes, grabs the public’s attention.’

That appears to have happened over the weekend – even more quickly than I had guessed. The horrific killings of two teenagers have propelled the issue to the top of the news agenda, with the Mail and the Mirror splashing today with the question “how many more?”, accompanied by photos of the 27 teenagers stabbed to death in the last year. It is a grim reminder of the human cost of a crisis which is occupying the fears of millions of parents around the country.

Such an appalling problem deserves to be on everyone’s minds, of course, and should compel politicians, police chiefs, and policymakers to reconsider whether their approach is really working. However, the risk I noted, of the demand to do something overtaking the importance of doing something effective, is all-too real.

It will in time affect Gauke’s prison reforms, I’m sure. But the immediate targets appear to be stop and search, and police funding.

On stop and search, calling for more is an easy and instantly popular headline. Everybody knows what the term means, and it is a straightforward tactic to imagine. However, there is a fantasy doing the rounds in which stop and search has been ended. It has not – there are still hundreds of thousands of uses of the power every year. Rather, Theresa May’s reforms as Home Secretary saw the tactic limited to a more targeted, suspicion-based power, and introduced new transparency measures about how and why it was used. The result, as Full Fact lay out here, is that while the number of stop and searches is down, the proportion which produce arrests or generate other useful findings is drastically up – ie the power is better-targeted than when it was simply used in a blanket way.

Changing that back comes with obvious costs. More police time would be used on stopping and searching people who are not carrying anything and who would not be arrested as a result, which seems a dubious use of limited police resources. And that means more innocent people caught up in such tactics, which has negative effects in itself.

On police funding, no doubt there are extra things that could be done with more money. There always are, in every public service. It is simple and clear to call for more police officers (a policy the Labour Party is promoting, even while its mayor of London opted not to do so in the capital), but again I wonder if this really amounts to a proper insight into the crisis that is facing us. As soon as austerity began, there were claims that it would directly spark a rise in crime – and yet the correlation did not appear in practice.

Even now, nine years into austerity (of a sort) I’ve yet to hear a convincing explanation of why it would be that after a lag of several years, some but only some types of crime are suddenly on the rise. And at the same time as police forces and the Police Federation tell us there isn’t enough money to fight violent crime, there is a steady stream of reports that various forces find the time to ring people up to tick them off about controversial tweets that are not even illegal. That doesn’t seem to fit with the message, somehow.

It may of course be that a change in tactics or increases in spending could have some effect on the knife crime surge. But if we are interested primarily in what works, not in simply demonstrating our toughness, then we ought to be more inquiring of the evidence, and to look more closely at what is going on.

For example, the Home Office’s own internal analysis argues that violent crime is rising because an oversupply of drugs has collapsed the profit margins of organised criminals, leading them to fight more viciously for territory and customers. And yet where is the discussion, by serious Conservative politicians, of taking any of the drugs market out of the hands of organised crime through decriminalisation?

To take another example, we can all see that this has become a crisis not just of violence but increasingly of violence involving children, often as offenders as well as victims. There are various vacuous laments by rote that youth club funding could somehow fix that – a position which is simultaneously patronising of the innocent majority and naive about the guilty minority (as Charlotte Gill argues in today’s Telegraph). But only rarely is there open discussion of the role played, or not played, by the families of teenagers who are going out armed onto the streets. Do they not know? Do they know but not care? Do they know and care but feel afraid or unwilling to turn in their own kids? Maybe finding out, and working out how to change that, would be a good start. Or we could just act tough and hope it works. Whichever you prefer.