It’s not, let’s face it, immediately obvious what to expect when Boris Johnson’s government announces it’s having a “crime week”. A natural response might be to check if your car’s been taken. But it turns out that ministers are against crime.

Some former cocaine users have gone on to be useful members of society. Others are in the Cabinet

We know this because the prime minister himself had dressed up as a policeman and gone on a dawn raid. The Downing Street Vanity Film Unit had gone with him and made a dramatic movie with a thrilling soundtrack, full of fast scary bass notes. The effect was only a little undermined by the fact that Merseyside Police had loaned Johnson an oversized hat and coat that left him looking like crime-fighting garden gnome.

The crime in question was drugs. There are, Johnson announced, 300,000 problem drug users in the country, and they commit a huge number of other crimes. The solution, he said, was rehabilitation. For instance, some former cocaine users have gone on to be useful members of society. Others are in the Cabinet. Frankly, there are questions to be answered about the enthusiasm with which the drug-sniffing dog in the film greeted the prime minister.

This is not the place for detailed statistical analysis, but it’s worth noting that pretty much every graph of drug use and drug deaths in the UK, both in prisons and among the general public, shows a decline until 2013 and increases since then. By coincidence, 2013 was the year the Ministry of Justice set out its plan to find “efficiency savings” in the system, a document signed by the then Justice Secretary, Chris Grayling. We are, as a nation, still coming to terms with the impact of Grayling usage over the last decade.

It’s not all bad news. “Crime has been coming down overall in the last couple of years,” Johnson said, and this is a rare time when it’s indisputably down to government policy. There definitely is less housebreaking when people are forbidden by law from leaving their homes, less shoplifting when shops are shut, and less car crime when there are no cars on the roads.

As Richard Nixon might have said: when the prime minister hosts it, it’s not a party

It wasn’t all one-way, of course. The lockdown led to the creation of entirely new crimes, which brings us to The Case of the Number 10 Knees-Ups.

Last year’s Downing Street lockdown parties exist in a space somewhere between the criminal law and a philosophy exam. When is a party not a party? If no one admits having attended a party, did anyone have fun?

Johnson himself has been careful not to deny that there was a party, only saying that no rules were broken, but on Sunday the Justice Secretary, Dominic Raab, said that a party would by definition have broken the rules, going on to imply that a party could not, by definition, have taken place. As Richard Nixon might have said: when the prime minister hosts it, it’s not a party.

In any case, Raab said, this was “something that took place a year ago”. This meant, he explained, that it wasn’t really something for the police, because “they don’t normally look back and investigate things that have taken place a year ago.” Even more so, presumably, when things didn’t take place, which they didn’t. Unless they did.

“I wasn’t there, by the way,” Raab went on. Presumably this shouldn’t be taken to imply the existence of a “there” where Raab could have been. Because there wasn’t, unless there was.

The problem, Raab explained, was that the questions about the parties are “hypothetical”, which they really aren’t, and also that the stories were based on anonymous sources. “We are chasing shadows,” he complained, briefly contriving to sound like a dogged investigator who had just run out of leads.

When Andrew Marr put it to him that he could, you know, ask someone if the parties had happened, Raab explained he was far too busy for that. He’s enough of a lawyer to know that the last thing you ask your client is whether they’re guilty. Especially if your client is Boris Johnson.

Raab’s fellow ministers clearly have their suspicions. Kit Malthouse simply told Sky News that he was taking Number 10’s statement that no rules had been broken “at face value”. This is a long way short of saying he believed it, although when pressed later by the BBC he eventually claimed he did, adding that he, like Raab, hadn’t been at the party that hadn’t happened. The Health Secretary, Sajid Javid, who is no fool, steered well clear of confirmation or denial. “The rules apply equally to everyone,” he told the Commons, and refused to be drawn further.

So there we had it. There may or may not have been a party or parties but no one has asked, although they are clear that all the rules around having parties were followed at all times at the party or parties, including the rule that parties were forbidden.

Finally on Monday, Number 10 explained that, in fact, they’d always said there hadn’t been a party. It has taken them five days to establish this, a delay which suggests that, in Downing Street at least, a bit of mandatory drug testing might be in order.