I would think wind would be a factor for roofers. Sudden wind gusts. Anyhow, there's several others. That was just one example. So, you can take any of these professions aside from that of police officer, and point out factors that would effect various locations. It all evens out.

You said that being a cop is the worst job in America. It's not even close. And, considering the eligibility requirements for pensions and even paid leaves, it's actually a very easy job, with exception to the rare event of taking live fire.