the world of infectious diseases: programs will often recruit former
sex workers to help change behaviour among workers who are still at
high risk.[19]
The first Cure Violence project started in 2000, in West Garfield
Park in Chicago. Why did they pick that location? ‘It was the most
violent police district in the country at the time,’ Slutkin said. ‘It has
always been my bias – as it is for many epidemiologists – to head for
the middle of the epidemic, because it’s your best test and you can
affect the greatest impact.’ One year after the programme started,
shootings in West Garfield Park had dropped by about two thirds. The
change had been rapid, with interrupters breaking the chains of
violence from one person to another. So what is it about these
transmission chains that makes interruption possible?
L in May 2017, two gang members
emerged from an alleyway in Chicago’s Brighton Park
neighbourhood. They were carrying assault rifles. The pair would end
up shooting ten people, killing two of them. It was retaliation for a
gang-related murder earlier in the day.[20]
Shootings in Chicago are often linked like this. Andrew
Papachristos, a sociologist at Yale University, has spent several years
studying patterns of gun violence in the city. A native of Chicago, he’d
noticed that shootings were frequently tied to social contacts. Victims
would often know each other, having previously been arrested
together. Of course, just because two people are connected and
share a characteristic – like involvement in a shooting – it doesn’t
necessarily mean that contagion is involved. It might be down to the
environment they share, or because people tend to associate with
those who have similar characteristics (i.e. homophily).[21]
To investigate further, Papachristos and his collaborators obtained
data from the Chicago Police Department on everyone who’d been
arrested between 2006 and 2014.[22] In total, there were over
462,000 people in the dataset. Using this information, they plotted a
‘co-offending network’ of people who’d previously been arrested at
the same time. Many of the individuals hadn’t ever been arrested with
someone else, but there was a large group who could be linked