There is much literature about psychoses associated with use of cannabis, usually temporary.. but sometime triggering underlying schizophrenic pre-dispositions.
It is a powerful narcotic.. without any PROVEN therapeutic benefits. It is also an intoxicant. The last thing you need in an on duty police officer with a car and a gun.
Anyone familiar with habitual use will know the pathological levels of paranoia, extreme subjectivity and inwardness, apathy and the distorted reality associated with drug.
Everyone i knew, with any sense, quit it in their mid 20s as simply too disruptive to their lives (as i did).