Sorry about your friend. 
But by far, most violence is committed by locals, people renting or owning homes.  
It simply isn't fair to take your frustration out on the thousands of people who have nothing and no one. One criminal assaulted your friend. Take it out on him, at least verbally. I strongly suspect any solution you come up with in your anger will commit a great deal of like violence on your fellow humans. There indeed are individuals who need strong action, including detention for long periods. 
If a community refuses to have a public shelter system, and Lane County does not have one, and if that community allows businesses to run off with jobs that pay the rent, then there will be thousands without shelter. If you have a solution that has any chance to help, make that known. All city centers have a devolving problem with poverty. 
You take the City of  Eugene to task and I would remind you Springfield has similar or worse problems, as does Portland. 
Hugh Massengill, Eugene