A lot of people who are homeless have mental health issues and are homeless due to those issues, it's almost like they need to be cared for in a mental health environment because being homeless isn't actually their problem.

A lot of people who are homeless have substance abuse issues, and are homeless due the those issues, it's almost like they need to be cared for in a substance abuse program because being homeless isn't actually their problem.

Once we whittle away the people who have issues that cause their homelessness other than just being homeless we can get to the people, who are either unemployed, under employed, or so debt ridden that they can't find a place to live.

This may be a coarse filter, but IMHO it's better than just shoving people into a "living space" and being done.