LAPD's sci-fi solution to real crime

Predicting where felons might strike is being made easier with a computer calculation

Los Angeles

Sergeant John Gomperz slows his black-and-white patrol vehicle to a crawl as he enters the parking lot of one of the shopping malls that litter the Los Angeles northern suburbs. For the next 15 minutes, he drives up and down, past McDonald's, Taco Bell, and a row of fast-food outlets. Then he pauses at the entrance of the electronics store Best Buy, and scans the horizon.

We're looking for people he considers "suspicious". These include lone, predatory males; youths cruising around on bicycles; and anyone who happens to be sporting gangland tattoos. "I'm trying to be highly visible," he explains. "Just because we don't see them doesn't mean they can't see us."

Eventually, after smiling at a few shoppers, waving to a casual acquaintance, and making a final lap of the car-park, Gomperz looks at his watch, winds up the window, and drives off. Job done, he announces.

To a casual observer, it might seem a waste of a quarter of an hour of valuable police time. But the way the sergeant sees things, the long, slow tour of a seemingly normal parking lot is one of the most important things he's done all day.

That's how things roll in the brave new world of computerised "predictive policing", a hi-tech crime-busting technique which Gomperz is helping to pioneer and which ,has the potential to revolutionise modern law enforcement.

The technique revolves around a single mathematical algorithm, developed by the University of California, Los Angeles. This complex equation can in theory predict, with pinpoint accuracy, where criminal offences are most likely to happen on any given day. Though that sounds like the stuff of science-fiction novels the principle is relatively straightforward. It mines several years' crime statistics to tease out hidden patterns. Once identified, they are projected into the future, to predict where cars might be stolen, or houses burgled, on any given day.

The forecasts are startlingly specific, and that's where the policing comes in. Each morning, Gomperz and his colleagues in the Foothill area of Los Angeles, where the technology is being tested, are given maps identifying a handful of "boxes" measuring 500ft x 500ft – the supposed crime hot-spots for that day. The officers are instructed to visit them as often as time allows. Once inside the "box", they make themselves as visible as possible. The shopping centre car-park which Gomperz has just slowly criss-crossed is bang in the middle of one of that day's boxes.

Computerised "predictive policing" is still in its infancy, but all the early signs are that it has a startling effect. In the city of Santa Cruz, California, where it was first trialled this summer, a 25 per cent drop in crime was recorded. Meanwhile in Foothill, a 50sq mile portion of northern Los Angeles, the number of non-violent crimes has dropped from around 50 a week to nearer 40, in the eight weeks since trials began. So striking have the results been that UCLA's system will this year be rolled out across Los Angeles, one of America's largest police forces. And it could soon be crossing the Atlantic. On 23 January, Captain Sean Malinowski, a LAPD officer who helped to develop the technology, will showcase it to delegates at the Defence Geospatial Intelligence conference in London.

"Anecdotally it seems to work. From the data we're seeing, it stops crime happening," Malinowski says, adding that an era of declining resources (the LAPD currently has a paid overtime ban), predictive policing can be a particularly valuable tool, since it isn't labour intensive. "If a suspect turns up, say, to steal a car, and he sees a police officer, then maybe that's enough to stop him committing a crime that day.

"Making arrests is still important. It keeps officers motivated. And in this trial, it has certainly been happening, when officers are in their boxes. But arresting people also takes up a huge amount of time. Booking one guy can take up most of a shift. So if we can reduce crime without doing that, so much the better." Malinowski struck on the idea for computerised predictive policing several years ago, when he was asked to supply UCLA with crime data for a research project. A bookish man, with an interest in academia, he began attending lectures there, and soon learnt that it was theoretically possible to use equations to model naturally occurring events such as animal population growths, or migration patterns.

In conjunction with several UCLA academics, he decided to create an equation which could model crime patterns. The algorithm they came up with uses three pieces of information about each crime – the time, date and co-ordinates – before teasing patterns out of the data.

Jeff Brantingham, a UCLA anthropologist who helped to develop it, says the ongoing trial in Foothill is using a randomised control. On some days, the co-ordinates of the boxes officers are asked to focus on are randomly generated; on others, they use the algorithm. "Comparing crime on the days we use the algorithm and the days we don't will give us a true gold-standard test as to whether it really works," he says. "We are also trying to measure appropriate dosage: how long an officer needs to spend in a box for it to be effective."

The concept of predictive policing is not without critics. Civil libertarians are concerned it might lead to life mirroring the film Minority Report, which starred Tom Cruise, in which police target people for crimes they might commit at some undetermined point in the future.

It also has legal complications. Under the Fourth Amendment of the US Constitution, police officers are forbidden from stopping a suspect without "reasonable suspicion" that they are committing a crime. No one yet knows whether simply being in a geographic box identified by a computer programme represents reasonable suspicion.

"What happens if officers turn up at a 500ft x 500ft area, on the look out for burglaries, see a guy with a black bag, search him and find it contains stolen goods?" wonders Andrew Ferguson, an assistant professor of Law at the University of the District of Columbia. "If that case goes to court, there will be the question of whether it was reasonable for the officer to suspect he was committing a crime."

If computerised predictive policing catches on, Ferguson expects a test case eventually to work its way up to the US Supreme Court. In the meantime, he expects noisy kickback from civil rights groups. "That a computer can effectively curtail the Fourth Amendment rights of individuals in certain areas would be particularly troubling to the civil liberties lobby," he says.

"There will also be concerns that if police wanted to target certain areas, or demographics, then they could simply tweak the algorithm to ensure officers visit certain neighbourhoods."

Back on the streets of Foothill, Sergeant Gomperz has no such concerns. He drives to another 500ft square box – this time at a park named after Ritchie Valens, the Mexican-American songwriter who wrote "La Bamba" and grew up locally. As we pull up next to a children's playground, a young man, with tattoos, cropped hair and a menacing pit-bull terrier catches sight of the patrol car. Seconds later, he turns around, and hastily disappears from the scene.

"Maybe he's going home to his mother. Maybe he doesn't have a licence for that dog. Maybe something way more sinister is going on," says Gomperz. "All I know is that he was here. He's seen us, and he's moving on. When I see that, I think maybe that's stopped him committing a crime. And that makes me think that this predictive policing thing really works."

Algorithms: Formulae for success

So what exactly is an algorithm? You could define it as a step-by-step problem-solving procedure, especially an established, recursive computational procedure for solving a problem in a finite number of steps. Or, to put it more simply, it's like a mathematical recipe, a set formula for finding your way through data.

Humble long division is an example of an algorithm that almost everybody would recognise. At the other end of the spectrum are the thousand character-long codes used for automated trades in the financial markets or the series of complex instructions that make up computer programs.

The man believed to have coined the term is the ninth-century Persian mathematician, Mohamed ibn-Musa al-Khwarizmi, who is also credited with giving us the word algebra, which like algorithm, derives from the Latin version of his name, Algoritmi.

Algorithms are put to good use in the 2011 film Moneyball, which stars Brad Pitt as a baseball coach who uses computer-generated analysis to pick a series of undervalued players who are gifted but affordable.

Portia Walker

News
More than 90 years of car history are coming to an end with the abolition of the paper car-tax disc
newsThis and other facts you never knew about the paper circle - completely obsolete tomorrow
Arts and Entertainment
Gay and OK: a scene from 'Pride'
filmsUS film censors have ruled 'Pride' unfit for under-16s, though it contains no sex or violence
News
people'I’d rather have Fred and Rose West quote my characters on childcare'
Arts and Entertainment
Hilary North's 'How My Life Has Changed', 2001
booksWell it was good enough for Ancient Egyptians and Picasso...
PROMOTED VIDEO
Have you tried new the Independent Digital Edition apps?
News
ebooksAn unforgettable anthology of contemporary reportage
Life and Style
Magic roundabouts: the gyratory system that has excited enthusiasts in Swindon
motoringJust who are the Roundabout Appreciation Society?
Sport
footballManchester City 1 Roma 1: Result leaves Premier League champions in danger of not progressing
Life and Style
The new Windows 10 Start Menu
tech
Travel
Bruce Chatwin's novel 'On the Black Hill' was set at The Vision Farm
travelOne of the finest one-day walks you could hope for - in Britain
News
Kim Jong Un gives field guidance during his inspection of the Korean People's Army (KPA) Naval Unit 167
newsSouth Korean reports suggest rumours of a coup were unfounded
News
i100
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Commercial Litigation NQ+

Very Competitive Salary: Austen Lloyd: NORTH HAMPSHIRE NQ to MID LEVEL - An e...

MANCHESTER - SENIOR COMMERCIAL LITIGATION -

Highly Attractive Pakage: Austen Lloyd: MANCHESTER - A highly attractive oppor...

Senior Marketing Manager - Central London - £50,000

£40000 - £50000 per annum: Ashdown Group: Marketing Manager (Campaigns, Offlin...

Head of Marketing - Acquisition & Direct Reponse Marketing

£90000 - £135000 per annum: Ashdown Group: Head of Marketing (B2C, Acquisition...

Day In a Page

Pride: Are censors pandering to homophobia?

Are censors pandering to homophobia?

US film censors have ruled 'Pride' unfit for under-16s, though it contains no sex or violence
The magic of roundabouts

Lords of the rings

Just who are the Roundabout Appreciation Society?
Why do we like making lists?

Notes to self: Why do we like making lists?

Well it was good enough for Ancient Egyptians and Picasso...
Hong Kong protests: A good time to open a new restaurant?

A good time to open a new restaurant in Hong Kong?

As pro-democracy demonstrators hold firm, chef Rowley Leigh, who's in the city to open a new restaurant, says you couldn't hope to meet a nicer bunch
10 best children's nightwear

10 best children's nightwear

Make sure the kids stay cosy on cooler autumn nights in this selection of pjs, onesies and nighties
Manchester City vs Roma: Five things we learnt from City’s draw at the Etihad

Manchester City vs Roma

Five things we learnt from City’s Champions League draw at the Etihad
Martin Hardy: Mike Ashley must act now and end the Alan Pardew reign

Trouble on the Tyne

Ashley must act now and end Pardew's reign at Newcastle, says Martin Hardy
Isis is an hour from Baghdad, the Iraq army has little chance against it, and air strikes won't help

Isis an hour away from Baghdad -

and with no sign of Iraq army being able to make a successful counter-attack
Turner Prize 2014 is frustratingly timid

Turner Prize 2014 is frustratingly timid

The exhibition nods to rich and potentially brilliant ideas, but steps back
Last chance to see: Half the world’s animals have disappeared over the last 40 years

Last chance to see...

The Earth’s animal wildlife population has halved in 40 years
So here's why teenagers are always grumpy - and it's not what you think

Truth behind teens' grumpiness

Early school hours mess with their biological clocks
Why can no one stop hackers putting celebrities' private photos online?

Hacked photos: the third wave

Why can no one stop hackers putting celebrities' private photos online?
Royal Ballet star dubbed 'Charlize Theron in pointe shoes' takes on Manon

Homegrown ballerina is on the rise

Royal Ballet star Melissa Hamilton is about to tackle the role of Manon
Education, eduction, education? Our growing fascination with what really goes on in school

Education, education, education

TV documentaries filmed in classrooms are now a genre in their own right
It’s reasonable to negotiate with the likes of Isis, so why don’t we do it and save lives?

It’s perfectly reasonable to negotiate with villains like Isis

So why don’t we do it and save some lives?