A friend that has been certified mentally ill stopped taking his meds and was fantasizing about killing himself, a family member and shooting up religious organizations. His doctor, family, employer and friends all called the police, talked to lawyers, mental health professionals, etc.
The end result was that he was facing sleeping in a car that was about to repossessed, and eating in homeless shelters. At that point he decided to accept free housing in exchange for seeking help.
His family’s only other recourse would have been to pay tens of thousands of dollars in legal fees to petition the court to force the police to uphold the law. This would have had a medium to low chance of succeeding.
Of course, during the months this dragged on, he missed an insurance payment or two (he had also been fired, divorced and evicted), so it lapsed.
There is a 12 (6?) month wait to get government disability insurance to kick in for this sort of thing, and the clock starts after the mentally ill person goes in for scary interviews with the government to establish they’re actually crazy.
The law used to handle this sort of thing properly in California, but Regan repealed the lions share of it as governor, and loopholes that accidentally allowed people like my friend to get health care have been progressively closed since them.
Nurses at the intake office of the appropriate mental health facility in Santa Cruz told me that most of the homeless people in the Boardwalk area there are in exactly the same situation as my friend was in, except they’ve been trapped in it for years.