OSCAR Slater didn’t kill Marion Gilchrist. Stefan Kiszko didn’t murder Lesley Molseed. Sally Clark and Donna Anthony and Angela Cannings weren’t responsible for any of their children’s deaths. On and on I could go.

There was Tim Evans, hanged for John Christie’s crime. Paddy Hill, ­Gerry Hunter, Johnny Walker, Billy Power, Dick ­McIlkenny, Hugh Callaghan – tried and wrongfully ­convicted of planting bombs in two central Birmingham pubs in 1974, killing 21 and injuring many more. Then there were the Guildford Four.

All of these innocent people spent long years of their lives in state custody, ­convicted by juries convinced the evidence against them was compelling. In another age, in another jurisdiction, any one of them might have swung and never lived to see the injustice meted out against them corrected.

Of the Birmingham Six, Lord Denning once lamented: “We shouldn’t have all these campaigns to get them released if they’d been hanged. They’d have been ­forgotten and the whole community would have been satisfied.”

And in his brutally cynical way, ­Denning might have been just about right. ­Confronted with the enormity of the crimes these men and women were ­accused of committing, and the public disgust aimed at these ­supposed killers of harmless ­pensioners, these terrorist cells and murderous mothers – you can understand why the social mood wasn’t exactly forgiving.

In the heightened atmosphere ­after a ­terrible crime, as public anxieties mount, the media goes wild and the police come ­under intense pressure to catch a ­perpetrator – there’s always a kind of ­collective catharsis that someone – anyone – has been ­detected, detained and put on trial. In that moment, the fact you’ve got the wrong man in custody doesn’t seem to matter a great deal.

Human societies have always created scapegoats. Social anxieties fall away in the most satisfactory way – even if the man or woman in the dock is wholly innocent of the crimes we’ve indicted them for. The moral order still feels like it has been restored.

This term, I teach a course about miscarriages of justice and why they happen. We began this week with the trial of Slater. ­Slater was sentenced to death in 1909 for the murder of Marion Gilchrist in her home in the west end of Glasgow. Slater was a German Jew with a louche lifestyle, various noms de plume, an ex-wife and a lady of the night as his domestic partner.

The prosecution’s case was that ­Slater had somehow gained access to the 82-year-old’s West Princes Street flat and had brutally done her to death, ­making off with a crescent-shaped diamond brooch from her dresser. Slater didn’t match any of the eyewitness descriptions of the man who stepped out of Gilchrist’s flat – given, respectively, by witnesses who saw him fleetingly from behind, a visually-impaired neighbour who wasn’t wearing his spectacles and a young woman who saw a running man briefly illuminated in a pool of gaslight on a bleak December night in Glasgow.

When it transpired that Slater had ­recently pawned a diamond brooch, the police were convinced they’d found their man. Banging down his door, they ­discovered that he’d done a bunk, ­taking the train for Liverpool then afloat on a ship for America. Convinced this was a flight from justice, they telegraphed ahead.

Slater was detained by the American authorities and shipped back to ­Scotland for trial. He must have been confident of his acquittal. He didn’t know ­Gilchrist. He had alibis for before, during and ­after her murder. Nothing ­incriminating had been found in his personal effects. And critically – that diamond brooch which led the police to his door? It wasn’t ­Gilchrist’s at all.

What was left was a paper-thin ­circumstantial case based on ­contradictory eyewitness reports, ­gingered up by ­Presbyterian Scotland’s antipathy to what it perceived as the gross moral turpitude of this religious and ­ethnic outsider and stranger. The police, nevertheless, were convinced they’d got their man.

Prosecuting, the Lord Advocate gave an inflammatory and inaccurate speech. From the judge’s chair, Lord Guthrie told the jury that a man like Slater didn’t ­benefit from the presumption of ­innocence. After the jury’s guilty verdict, Guthrie sentenced him to death.

The National Records of Scotland still keep the macabre little prison ­notebook where his HMP Peterhead warders kept tabs on their prisoner’s appetite, to ­ensure the rope for Slater’s long drop was cut the right length for his weight. ­Hanging a man seems barbaric enough, but there’s ­something particularly ­ghoulish about all the practical and human apparatus which supposedly civilises this official kind of murder. Slater didn’t die – but his late reprieve left him incarcerated for 19 long years at hard labour before the new ­Appeal Court finally quashed his ­conviction in 1927.

Almost a century after Slater was ­released, step forward the new deputy chairman of the Conservative Party. Lee Anderson, like Priti Patel before him, seems intensely relaxed about imposing the ultimate sanction on potentially innocent people if it wins him a sympathetic write-up from the feral media. We should be savvy about the PR game being played at our expense, and how it is played.

The National: Lee Anderson

The Nottinghamshire MP has already an established reputation for being bluff, glib and reactionary. True to form, in an interview last week, he voiced his ­support for the restoration of the death ­penalty on the basis that “nobody has ever ­committed a crime after being executed”. “You know that, don’t you? 100% success rate.”

The euphemism for politicians like ­Anderson is “outspoken”.

On one level, Anderson’s appointment as a key media proxy for the Conservative Party can only be read as a sign of Sunak’s weakness – personally and politically. Lacking the common touch himself, he has been forced to genuflect to the Farageist wing of the party which has now been folded back into their voting base after the demise of Ukip. With Anderson, Sunak knows what he’s getting – a chain reaction of headlines.

He embodies the tendency for ­“owning the libs” to become the key priority in right-wing political communication. It isn’t about communicating policy ideas or a positive political agenda – but winding up your opponents. As political strategy goes, it’s essentially trolling in a suit and tie. And for the public? The message is: the people you hate hate me. Vote Tory.

When the EU Withdrawal Agreement ­finally staggered over the line, some knackered Remainers consoled ­themselves with the thought that Britain’s departure from the European Union would at least drew a line under the cultural conflict.

There would be no more Boris ­Johnsons, propelled into power by tall tales about bendy bananas and barmy Brussels ­regulations. Ukip would be ­defanged. Having got everything they wanted, the xenophobe right would head off for a snooze, satiated, dreaming of nothing more sinister than a return to imperial measures and dimpled pint glasses.

This prediction seemed desperately ­naive at the time. Experience has exposed just how daft it was. Barely a week goes by in British politics without the Tories trying to parlay some kind of European conflict back into public affairs. Sometimes it is Northern Ireland. Mostly it’s still immigration, asylum and boats.

Last week, “sources close to” Sunak hinted darkly that ECHR withdrawal might still be contemplated. And now those beastly Europeans are preventing us rolling out a socially improving scheme of public executions.

I know these are deeply unserious people. I know that Anderson’s remarks are just bait – and I’ve gulped it down, line and sinker. But be serious about what they’re saying. When you hear loudmouth populist politicians advocating the ­restoration of the death penalty, ask them about Oscar Slater.

Ask them about Clark – convicted of the murder of her two baby sons after an incompetent Home Office ­pathologist repressed scientific evidence suggesting they both died of natural causes, and knighted paediatrician Sir Roy Meadow took it upon himself to enter the ­witness box to tell the jury that the chances of Clark’s ­family experiencing two cot deaths were “73 million-to-one”.

This was statistically bogus and ­outside Meadow’s expertise – but it was enough for Clark to be convicted. ­Public ­vilification and three years of ­imprisonment followed, before the cracks in the prosecution case were revealed, and Clark’s convictions were quashed. Like many victims of wrongful convictions, she died young just a few years later.

Ask them about the Birmingham Six and the Guildford Four. As journalist Chris Mullin pointed out last week, the wrong people “were convicted of all the main IRA bombings of the mid-1970s” in the UK. Would justice be served by 18 graves full of the bones of 18 innocent men?

These are real people, real lives, and real injustices – not a punchline for a clown.