John Wilson is accused of brutally stabbing Kelli O'Laughlin in her home last month.
The man accused with killing a 14-year-old Indian Head Park teen said he's long-battled with mental illness, court documents show.
But that doesn't necessarily mean John Wilson is incapable of controlling himself or doesn't understand his actions, according to University of Chicago psychiatrist Daniel Yohanna.
"Most people with mental illness are not dangerous, they don't commit violent crimes. But the best indicator is history of violent crimes usually predicts future [ones]," said Yohanna. "Most people with mental illness understand the law [and] they understand right from wrong."
Wilson is accused of brutally stabbing Kelli O'Laughlin in her home last month. But the charges against him are a first. His criminal history, which kept him behind bars for 17 of the last 20 years, include convictions for carjacking, spitting on a prison corrections officer, possessing a stolen vehicle, robbery and drug possession.
Wilson said he's been getting psychiatric help since his pre-teen years, and he said he suffers from both depression and borderline personality disorder.
Yohanna said that one of the best ways to prevent violence is to treat mental illness.
"The real key is to provide treatment both in prison and after people are out of prison," he said. "They need to continue to get treated. That lowers the risk of violence."
Indeed, a condition of Wilson's parole last year was anger management and outpatient mental health treatment.
But with the state grappling with a budget in the red, millions of dollars are being cut from mental health budgets in the city and the state, further fraying the safety net to manage and treat mental illness.
Wilson's brother said Wilson didn't get the proper rehabilitation he needed during his years in and out of prison.
"My little brother is crazy. I told the judge this in Skokie. I told him this already. My little brother has a serious problem," he said last week.