Reduction in Crime

• In New Haven, Connecticut a 10% increase in tree canopy was associated with a 14% decrease in property crimes and a 15% decrease in violent crime.Troy, A., Nunery, A., and Grove, J.M. (2016). The relationship between residential yard management and neighborhood crime: An analysis from Baltimore City and County. Landscape and Urban Planning, 147, 78-87.
• Similar results were found in Baltimore, with a 12% drop in all outdoor crimes for each 10% increase in canopy.Troy, A., Nunery, A., and Grove, J.M. (2016). The relationship between residential yard management and neighborhood crime: An analysis from Baltimore City and County. Landscape and Urban Planning, 147, 78-87.
• A public housing development in Chicago had 48% fewer property crimes and 56% fewer violent crimes in or around buildings with more greenspace.Kuo, F. E., and Sullivan, W.C. (2001). Environment and crime in the inner city: Does vegetation reduce crime? Environment and Behavior, 33(3), 343-367.
• However, some criminals are benefited from vegetation. Automobile thieves in Washington, DC were more likely to target cars parked in areas with higher vegetation so their activities could be concealed.Kuo, F. E., and Sullivan, W.C. (2001). Environment and crime in the inner city: Does vegetation reduce crime? Environment and Behavior, 33(3), 343-367.

Perceptions about Vegetation and Crime

• A common perception is that urban vegetation is associated with higher crime rate by allowing criminals to conceal themselves.
• This is not a new phenomenon, as laws from 13th century England require landowners to clear the area around highways so “no cover for malefactors shall be allowed.”Kuo, F. E., and Sullivan, W.C. (2001). Environment and crime in the inner city: Does vegetation reduce crime? Environment and Behavior, 33(3), 343-367.
• In the present, attitudes about urban vegetation are marginally shaped by social factors such as age and gender, but mostly by the condition and phase of succession in a vegetated area.Jansson, M., Fors, H., Lindgren, T., and Wiström, B. (2013). Perceived personal safety in relation to urban woodland vegetation – A review. Urban Forestry and Urban Greening, 12(2), 127-133.
  

Why Less Crime?

• There are several theories as to why crime is lower in areas with higher tree canopy.
• Well cared for green space also shows potential criminals that the residents or businesses in an area care for and respect the community.
• When a community cares about its space, they are more likely to be active in the outdoor aspects of it.Troy, A., Nunery, A., and Grove, J.M. (2016). The relationship between residential yard management and neighborhood crime: An analysis from Baltimore City and County. Landscape and Urban Planning, 147, 78-87.