According to the police report of the incident, which police initially said was confidential, 11 days before Officer Walters came across Collins bleeding from self-inflicted wounds at the arboretum, Collins had gone to the Portland Police to make a confession.
Collins told police that he believed he molested a girl 42 years ago. He couldn't really remember her name. He didn't know where she lived. He had not spoken to her since. But he wanted to tell the police what happened. From the report (pdf):
A few of Collins' friends told me he was a cutter. Jason Renaud, of Portland's Mental Health Association, helps explain why people sometimes turn to cutting themselves. "Cutting is an unusual symptom of mental illness. It’s usually seen in young people, but can be seen in older people. It’s a response to feeling bad about yourself, bad about your environment. It’s hard to treat, people are usually pretty secretive about it. It’s a way of harming yourself without killing yourself."
Sad sad sad sad sad.