Although laws may be slowly changing in some states, it is often difficult to get people the help they need before it's too late.
Keep in mind, although this highlights the violence that can transpire when people with mental illness don't get treatment, the vast majority of people who have a mental illness are not violent!
In fact, studies show that mentally ill people are no more violent than others in the general population.
However, people who have a dual diagnosis (ie. mental illness with drug addiction) do show increased violence if they are not adherent to their medications.