Thanks to The Wire, who can resist conjuring images of ghetto projects and rampant crime when thinking of the fine city of Baltimore? Indeed, Baltimore’s crime à la HBO is out of control. Someone should have told Detective McNulty he could have skipped five seasons’ worth of pager taps, drug raids, and binge drinking if he had only been armed with a real crime-stopping weapon: trees.

That’s right, trees. Like the big, green, CO2-sucking kind. It turns out that in addition to housing squirrels, they also reduce lawless activity. This is the conclusion drawn by a team of researchers who teased apart the relationship between tree canopy and crime in and around Baltimore. They used aggregated crime data from Spotcrime and overlaid it with high-res satellite imagery to conduct probably the largest analysis of its kind to date.

According to the study, a 10 percent increase in trees roughly equaled a 12 percent decrease in crime. “It’s really pretty striking how strong this relationship is,” says Austin Troy, director of the University of Vermont’s Transportation Research Center and lead author of the study, published in the June issue of the journal Landscape and Urban Planning.