Well, I live in a city (Austin, Texas) that under the last mayor attempted to stop using police to deal with homelessness. Unfortunately, what it did not do was come up with homes for them to live in. The result was a lot of very visible homeless encampments, surrounded by garbage, that resulted in a big negative turn in public sentiment regarding the homeless.

It turns out that the way you solve homelessness, is you build more inexpensive places to live. Houston (approvingly cited in this article for their progress on homelessness) is known to be one of the easiest cities in America to build. Austin is known for being very difficult to build in (regulations, lawsuits, etc.). The results are pretty predictable.

I'm not sure what is served by putting the emphasis on whether or not the police are involved; even the people he quotes are ambivalent about that. Either you have places for people to go, or you don't. If you don't, they will be homeless. How you do or do not get police involved is not really going to change that one way or another, and I can say that from personal experience, because Austin tried removing the police from the situation and nothing got better.

The (only) way to help with homelessness, is to have enough homes for everyone.