The issue here is not skilling these people in trades, it’s really about working on mental health and the underlying reasons why they are in prison. Until those challenges are addressed, these people mostly will not succeed. Many have not experienced much of a « normal » family life or friendships that promote personal growth, or mentorship.
On top of that, when many are released they have nothing. So, imagine trying to stay employed for a week when you have nowhere to live (especially hard to rent a place also when you have a record[1].
Anyway, we might know how to reduce recidivism, but society sure doesn’t seem interested in taking the steps to invest what’s needed.
[1] I recently spoke in front of the Colorado Senate concerning Assembly Bill 99 which will auto-erase the records of non-violent offenders in the state with some outcomes being that they can more easily find employment and rent places to live.