In the Neighborhood: Environmental Features Associated With Teen Homicide

Mar 7 2016

In the Neighborhood: Environmental Features Associated With Teen Homicide

teen homicideIt is not a pretty picture. Boarded up, dilapidated buildings. Overgrown vacant lots filled with debris. Security bars on homes and businesses. A landscape of disorder surrounds many urban youth who are at higher risk of homicide. A new study took a close look at Philadelphia neighborhoods to determine if certain environmental features could be associated with youth violence.

“A lot of blighted areas can erode the sense of security in a neighborhood and make people less likely to spend time outside in those spaces, and sometimes it can bring on opportunities for crime,” said Alison Culyba, MD, MPH, an adolescent medicine physician in the Craig-Dalsimer Division of Adolescent Medicine at The Children’s Hospital of Philadelphia, who was an integral part of the research team of epidemiology and violence prevention experts from The Children’s Hospital of Philadelphia and the Perelman School of Medicine at the University of Pennsylvania.

The researchers conducted a unique, multifaceted study of teen homicides that occurred outdoors in Philadelphia. Their results, which appear online in JAMA Pediatrics, point toward neighborhood elements that could be good candidates for revitalization efforts. Prior work looking at low-cost place-based interventions to remediate urban land and buildings has shown promise in terms of reducing crime and violence as well as other negative health outcomes.

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Alison Culyba, MD, MPH, is a physician in the Craig-Dalsimer Division of Adolescent Medicine.


“Those findings motivated our work to uncover associations between features of the built environment and homicide, with the idea that we could potentially identify specific, modifiable neighborhood features that could be targeted in future place-based interventions to reduce violence in urban neighborhoods,” Dr. Culyba said.

Based on data from the Philadelphia Medical Examiner’s Office, the researchers identified 143 homicide victims age 13 to 20 from 2010 to 2012 who lived in Philadelphia. The Philadelphia Police Department provided additional details about the crime scene and circumstances of each homicide.

The study team recruited 155 matched control participants in the same age range who were also outside in Philadelphia at roughly the same time that each homicide took place. The researchers had to act quickly in order to find control participants who could recollect their whereabouts outdoors in the city within a three-hour window before or after each homicide had occurred. The study team then compared the homicide locations with the locations of control participants in terms of differences in the streets, buildings, and natural surroundings.

“Our goal was to say, at this particular time, on this particular day, what were the surroundings like for a kid who died versus a kid who didn’t suffer an injury, and what can we learn in terms of place-based factors that put adolescents at risk for homicide?” Dr. Culyba said.

Within two weeks after each homicide event, field researchers photographed the immediate surroundings where the homicides took place to create 360-degree, high-resolution panoramic images. They also photographed the locations where the control participants reported being on the same day and time. Trained coders examined the images to identify 60 visible, environmental elements, such as displays of graffiti or homes with broken windows.

While the researchers acknowledge that homicides stem from a complex interplay of factors at individual, family, community, and socioeconomic levels, results of this study contributed new evidence about the potential role of physical surroundings in shaping violence. In examining features of the natural surroundings of participants, the presence of a park or a maintained vacant lot were both associated with significantly lower odds of homicide.

Indicators of frequent pedestrian activity, such as street lights, illuminated walk/don’t walk signs, and public transportation stops, were significantly associated with lower homicide. In contrast, stop signs were associated with higher odds of adolescent homicide, perhaps because they are markers of less travelled intersections in residential neighborhoods and present more prospects to covertly commit severe crime.

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Charles Branas, PhD is the study’s senior author and director of the Penn Injury Science Center./p>


“Initially, we were somewhat surprised to find such strong associations with street infrastructure, which you typically think about around pedestrian injury and motor vehicle safety but not so much around homicide,” said Charles Branas, PhD, the study’s senior author and director of the Penn Injury Science Center. “One theory that resonated with a lot of the things we found points to the importance of busy streets in promoting outdoor activity, interaction, and cohesion in communities, which could potentially deter street violence.”

While this new study shows associations between certain neighborhood elements and teen homicide, Dr. Culyba pointed out that the findings do not demonstrate cause and effect. However, they do importantly highlight potential targets for future intervention studies. Future experimental research is needed to make actual changes to city spaces and see if those changes make a difference in urban violence. For example, if volunteers remediate vacant lots by mowing the lawn and creating a manicured community garden, will it promote safety for adolescents who live nearby?

“Adolescence is a time of tremendous cognitive development,” Dr. Culyba said.  “For many urban teens, assessing and lessening the risks they face — how to get to school safely, how to hang out and play basketball without facing violence — poses a huge challenge. Place-based interventions may be particularly important for them.”

Already, other research has recognized the impact of vacant lot greening on reducing less severe crimes, and has also demonstrated that mixed urban residential neighborhoods with good walkability can promote physical activity and improve mental health.

“It’s encouraging that some of our findings are in line with the idea that you may be able to better design or change city spaces and have an impact on multiple health indicators at the same time,” Dr. Culyba said. “Now our job is to figure out exactly which are the best design strategies.”

The study team included several of Dr. Culyba’s colleagues who also are interested in factors that shape the risk of urban youth violence. Dr. Branas and Sara Jacoby, PhD, MPH, are in the department of Biostatistics and Epidemiology at UPenn; Therese Richmond, PhD, CRNP, is in the School of Nursing at the University of Pennsylvania; and Joel Fein, MD, MPH, is director of Advocacy and Health Policy for the Division of Emergency Medicine at CHOP, co-director of the CHOP Violence Prevention Initiative, and a professor of Pediatrics and Emergency Medicine at UPenn. Dr. Culyba also is an adolescent medicine consultant to CHOP’s Violence Intervention Program, and is a PhD candidate at UPenn.

For more information, see the full CHOP press release and UPenn press release.