at that board, telling a newspaper quote, i feel like they are responsible. members of that board didn t return our calls or e-mail. if we don t want people to get treatment, we created a great scenario to do that. reporter: treatment advocate doris fuller says cuts in psychiatric care have been happening for decades. when states close mental hospitals because of neglect and abuse, she says, they didn t build adequate replacements. today, we have about 450,000 people with mental illness living in jails and prisons. reporter: why did the united states just cut resources for the mentally ill over the past several decades? let s look at who those hospitals served. they serve a population that has no voice, a population that does not vote. reporter: the result, according to fuller, an increase in rampage shootings and other killings committed by the mentally ill. she says right now, about 10% of all homicides in the u.s. are committed by people with untreated mental illness.