It rather depends on what you think the police are for

We admit to sometimes being a little archaic around here. For example, in our attitudes to freedom and liberty. And so it is with our attitude towards policing: we are rather Peelite in what we think the entire game is about. We thus disagree with the police in this particular matter:

A gadget that alerts speeding drivers when emergency vehicles are nearby was last night facing calls by police and motoring organisations to be banned.

... a dashboard-mounted device which, astonishingly, is perfectly legal, according to its makers.

It can detect when police cars – even unmarked vehicles – are more than half a mile away by picking up encoded radio signals, and then sends a warning to the motorist.

When a 999 vehicle is within 1,200 yards, it sets off a green light on the display. As it gets nearer, the lights go to amber and finally they go red when it is just yards away. The device can even detect the radio signals from police officers on the beat and force helicopters.

... But last night Gwent Police Crime Commissioner Ian Johnston called for them to be banned.

He said: ‘This device is a passport to villainy and there is no legitimate reason for a law-abiding person to have one. The sellers are being very naive if they believe that they will be used to reduce accidents.

‘A criminal will carry out a drug deal, see a light on their dashboard and then ditch their illegal stash, only to pick it up when the police aren’t around – or a motorist will be speeding on the motorway, an alert will pop up and they’ll slow down.’

Devices that detect the position of speed cameras are legal for use on UK roads. Several years ago, legislation was proposed to make detectors with radar and laser illegal, but the ban did not go ahead.

If you think that the purpose of the police, of having a criminal justice system at all, is to punish the bad guys then you will be on the side of the police here. But if you are, like us and Sir Robert, of the belief that the having of those police, that justice system, is to reduce the number of bad things that happen then you will be entirely happy with this device. For, in that speeding example, it is not true that we wish to punish those who speed. We wish to reduce the amount of dangerous speeding that goes on, that's our primary goal. And if this comes about without having to punish anyone because people are not speeding then we are happier at that outcome than we would be if we had to expend resources to punish those who had sped.

It is exactly the Peelite argument: the police should reduce the amount of crime simply by their existence, by their presence. Punishment is only a back up to that idea. And here we have gadgetry which increases the amount of crime that does not happen for any particular police presence. It is a multiplier of the power of policing itself to achieve our goal. And who wouldn't want that?

Where the US justice system is and isn't racially biased

In a timely post Scott Alexander investigates the evidence around the US justice system to see where, if at all, it is systematically biased against African-Americans. He looks at quite a lot of empirical evidence and concludes that:

There seems to be a strong racial bias in capital punishment and a moderate racial bias in sentence length and decision to jail.

There is ambiguity over the level of racial bias, depending on whose studies you want to believe and how strictly you define “racial bias”, in police stops, police shootings in certain jurisdictions, and arrests for minor drug offenses.

There seems to be little or no racial bias in arrests for serious violent crime, police shootings in most jurisdictions, prosecutions, or convictions.

This is important given the news coverage of the killing of Michael Brown, an 18-year old African-American in Ferguson, MI, by a white police officer. Although a lengthy grand jury investigation found that the police officer did not act unlawfully, many have rejected this verdict.

They may be motivated by a belief that the justice system is predisposed to exonerate white police officers who act wrongfully to racial minorities. This is a phenomenon I have written about in the past – one has to use one's existing beliefs to assess new information to make sense of the world at all. But Alexander's investigation of the evidence suggests that things may not be as clearly biased as they believe (or, indeed, as I did before reading the post myself).

Alexander makes an important point, however. Although law enforcement may be less biased in the US than we think, the laws themselves may still be very biased (even if that bias is unintended, which perhaps it is). Drug laws, which seem extremely unjust, will cause more injustice to African-Americans if they use drugs more regularly than other racial groups. And then there is the fact that African-Americans may be poorer on average than than white Americans, so they cannot access the same quality of legal defence.

The lesson from this may be that, though we can never escape the 'webs of belief' we construct to understand the world, we can try to be aware of the fact that we use these. If instead we decide to view disagreements about politics as existing because bad guys have incentives to fight good guys, we may end up in dark places where no amount of evidence will ever convince us that we may be mistaken.