Same reason you work as a Military Officer or any other job.

Pay, sense of purpose and duty, love of the job, benefits, security and personal reward and achievement.

Cops actually make good money. If I had 7 years with Texas State Troopers is be making $62k there. That's nothing to sneeze at considering the low cost of living. They also have actual retirement pensions, not some piece of shit 401k match.

So I went back and click on that link.

"Michael David Dunn (white vigilante)"

The sad state of education. It is no wonder people can't tell the difference between your, you're anymore.