The police, many times a day, receives a call or tweet about how the homeless are disturbing their neighborhood, committing crimes, and leaving drug paraphernalia and trash. When the police get there, they see a crime scene or trash, and they see homeless folks, but they don't see any direct evidence between the two subjects. But they move the homeless along, because offended housed people are more important than homeless people trying to survive.
Yes, there are homeless people who commit crimes. So when you see them do crimes, go ahead and call the police. Otherwise, don't make assumptions, and don't call the police because you don't like homeless people in your neighborhood. The police have better things to do than to harass the poor.
And so, might I suggest, do you.