This would probably be the case for the imagined suburban neighborhoods in the article. Select cities in the USA (notably NYC and LA, perhaps SF as well) have disproportionate homeless population because people travel there to live a homeless lifestyle. I personally know people who moved hundreds of miles away to one of these cities for easy access to drugs and opportunities for prostitution.
Your average walkable suburban center would likely have a pretty limited homeless population, and locals would be familiar enough with them to recognize whether or not they are a potential threat.
Your average walkable suburban center would likely have a pretty limited homeless population, and locals would be familiar enough with them to recognize whether or not they are a potential threat.