It depends on what auto insurance company you are with. Some auto insurance companies offer discounts for certain occupations while others don't. The most common types of occupations that they give discounts to includes police officers, doctors, nurses, teachers, first responders, those in the military, etc. It just really depends on the insurance company.
Your best bet is to call your insurance company and ask if they offer occupational discounts. If they don't you can try calling other insurance companies and ask them the same question. Even if they do offer this type of discount that doesn't necessarily mean other insurance companies will have an overall better rate, though. The occupational discount is usually in a range of 2-9% or so roughly.
When you apply for this discount you also have to supply written information showing who they work for. So, a police officer would supply the insurance company with a document stating his employment on his department's letterhead. When the insurance company gets this proof is when they apply the discount.