My nonprofit runs a homeless program in Los Angeles. I can assure you the huge majority of homeless have severe addction and/or mental problems.

You can't force anyone into a shelter or into treatment. Most can't/won't abide by shelter rules, so it's the streets for them.

The mayor recently started a task force on the homeless problem in OKC and seemed to have some real compassion around the issue. I hope things improve for everyone soon.