With 91 percent of our prisoners having a mental health or substance abuse disorder, mental illness has become a major problem for New Zealand's justice system.
It's costing taxpayers millions and prison isn't the best way to treat them, mental health advocate Michelle Kidd says.
But there aren't many options for judges to help mentally ill people when they end up in court for petty crimes or nuisance offences, she told The Nation on Saturday.
"Our judicial system and our criminal justice system has almost become the last point before total despair."
Nearly one in two Kiwis will experience a mental illness or addiction in their life time, mental health advocate Arana Pearson says.
For some people these conditions will disturb the way they think, their perception and how they regulate their emotion.
In the criminal justice system, mental health rates have soared.
- 35 percent of those proceeded against by the police have a mental illness or addiction.
- 40 percent of those charged in court have a mental illness or addiction.
- 51 percent of those starting a community sentence have a mental illness or addiction.
Psychiatric doctor Coni Kalinowski and her colleague, mental health nurse Sally Crene, say substance abuse often goes hand-in-hand with a mental health crisis.
"We see people who have psychosis of various sorts, people who are manifesting post-traumatic symptoms, people with extreme anxiety - the full spectrum of substance abuse," says Dr Kalinowski.
William Smith was one of those people, when he was shot by police in 2012 after threatening officers with a spade.
He says for years he chose to ignore his depression and anxiety, and self-medicated with alcohol. He says he now realises why he turned to crime.
"I do have regrets for what I put people through, I do. I was responsible for it."
He doesn't have animosity towards the police who shot him, and says they were doing what they needed to do.
"If they hadn't been there it could have escalated into something totally different."
Nation reporter Mike Wesley Smith, with help from the Mental Health Foundation, investigated the scale of the problem of mental health in crimes, and the police response. This is part one - watch parts two and three online.
Watch the video for the full report.