I agree with SteveinMN about a) training and b) budgeting to prevent excessive overtime and c) cut back on the militarization of municipal police.
I think another solution is to provide a paid sabbatical to police officers and correctional officers.
I agree these are high stress careers, and burnout would be a big issue. I believe companies like Intel still provide paid sabbaticals every 7 years to their employees. I would be in favor of paying a bit more in taxes if this could be implemented.