Patients admitted to the Idaho Security Medical Program spend months, on average, in cells like this one in a state prison near Boise.(Sarah A. Miller
/ ProPublica)

Idaho is about to become the only state in the nation that puts patients who are labeled "dangerously mentally ill" but who have not committed any crime in prison.

This is nothing new for Idaho, which has been putting people suffering from mental illness behind bars since at least 1954.

Why does this happen? How does it affect people? And is this constitutional? These are all questions that the nonprofit newsroom ProPublica set out to answer and reporter Audrey Dutton joined Idaho Matters to tell us what she found.