If they are actively violent and have committed a crime, hold them until their (expedited) court date (while providing them the option to explore support/therapy and/or access to spiritual counselors), record examinations by psychiatrists/perform them with outside/impartial observation, give the accused legal representation, and let publicly observable courts decide their fate. The option of a jury, witness/family/etc. testimony, and second opinions is imperative to their human rights.
If they have committed no crime (homelessness or being unable to provide for your needs are not crimes), are not violent, and are not a direct threat to themselves or others (and there is no concrete evidence that they will be) - there's nothing you should be able to do to violate their will.
In the latter situation, the best you can do is try to earn their trust and ensure they are provided an environment where they feel safe - providing them with every social support and alternative that they should be entitled to explore for their betterment.
Impoverishment and homelessness are issues that society, and capitalism at large, refuse to address with real solutions. Those solutions are too expensive to those that make policy.
A housing crisis, a depression of wages and rise in cost of living, inaccessibility of timely and cost-efficient health care interventions (mental or otherwise), inaccessibility of drug rehabilitation and a system that punishes drug use criminally, and having no social safety net (to prevent such occurrences of homelessness and lack) is the recipe that creates the situations that these individuals experience.
The headline is not accurate, read the article.