Crime Scene

Greater Manchester Police are to field test a new Cambridge University initiative to cut crime by focusing police officers on "pressure points" known for their high level of offending.

This will be the first controlled experiment in history which allows us to assess not only whether this patrol design will reduce crime in those areas, but also whether it just encourages offenders to go elsewhere.

Professor Lawrence Sherman

The experiment, which is described in a short video released today on the University's website and YouTube, will test the effectiveness of focusing resources on hundreds of small areas through Greater Manchester. None of these covers more than a few hundred feet, but each has a high rate of violent crime.

It will investigate the theory that one constable can deter more crime by checking a series of these individual hotspots than by making less structured patrols across a wider area or beat.

The project is being led by Professor Lawrence Sherman, Wolfson Professor of Criminology at the University of Cambridge, where he directs the Jerry Lee Centre of Experimental Criminology. Professor Sherman will meet senior officers from Greater Manchester Police this week to finalise arrangements, with a view to starting the research in the spring and publishing the results next year.

"This will be the first controlled experiment in history which allows us to assess not only whether this patrol design will reduce crime in those areas, but also whether it just encourages offenders to go elsewhere," he said.

"We believe that simply by having a police officer stationed in the middle of one of these pressure points we can spoil the party for would-be offenders and stabilise the area. If the experiment produces the results we hope it will, we could end up revolutionising policing by putting officers not on neighbourhood beats, but focusing them heavily on these pressure points."

The idea is based on earlier American tests of policing crime hotspots which Professor Sherman developed in the late 1980s. In 1987, he discovered that just 3% of the street addresses in Minneapolis produced more than half of all calls to police. In parts of the US, concentrating police on these streets has since successfully cut crime by two-thirds within the hotspots. What remains unknown from US studies is how much this strategy may encourage offenders to commit crimes at other locations.

The idea of systematically mapping police patrols so that they focus on a list of long-term pressure points has never been subject to a controlled test in Britain. The effects may not be the same as in the US, where street layouts and other factors are quite different. Greater Manchester Police will essentially be leading the world's first experiment to answer that question.

Since Professor Sherman first published his research on these issues, police forces have interpreted "hotspots" differently. In the UK, the term commonly refers to much larger areas than in the US. Entire police divisions, metropolitan boroughs and even cities have been branded "hotspots" for an assortment of crimes. Criminologists, by contrast, regard hotspots as tiny areas where one officer can observe everything that is happening. The new project follows this more scientific definition.

The experiment will divide 200 hotspots into two groups. The first will be policed normally, but in the second, the police presence will be intensified with officers stationed in pressure points for many more minutes during high-crime periods. Researchers will then test the comparative effects over the course of about a year, measuring the average change in crime over time in one group with that of the other.

"We believe that once we start targeting these pressure points, crime will fall significantly," Professor Sherman said. "In theory, if you can prevent offenders from committing crime in these areas, it may be possible to stop them altogether. The question is whether that theory works, which is what we are aiming to find out."

The study is the first in an unprecedented series of controlled experiments in British policing under the Tactical Experiments and Strategic Testing (TEST) Programme led by Greater Manchester Police, in collaboration with the Jerry Lee Centre for Experimental Criminology and several other UK police forces. In the same way that certain hospitals undertake clinical studies, the aim is to test different research in the science of crime with the police, enabling them to develop new and cost-effective approaches to making communities safer.

Greater Manchester Police Chief Constable Peter Fahy said, "We already know that a small number of areas account for a disproportionately high proportion of crime in Greater Manchester."

"At the same time the public are demanding more police to be present in the areas where they feel unsafe. This experiment will allow us to test out the impact of concentrating on some very particular areas and see whether it has the same effect as in some American cities."

"This is part of a wider change programme within GMP to ensure that our effort is focused where it will most reduce crime and disorder."

The film, "The Crime Experiment", can be viewed by clicking on the links to the right of this page.


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