I'm a bit stumped about this; the one thing I do remember is Linda Wang's 2007 article about UC Berkeley chemistry graduate students teaching prisoners in San Quentin.
I would imagine that jobs that require work around sensitive chemicals (scheduled drugs, for example) are out of the question. I presume that environmental/agricultural QC-type positions might be doable?
Readers, if you have suggestions, I would be interested in hearing them. Also, do you know someone who has spent some time in prison that has gotten a job as a chemist?