When you get a chance, take a look at the Officer Down Memorial Page at www.odmp.org. Start reading back through the stories of the circumstances of some of the officers' deaths. While it isn't an everyday occurrance (thank God), there have been many officers who have been ambushed or hunted. Off the top of my head there was the Lexington officer a few years ago, the officers in the Seattle coffee shop, and a Puerto Rican officer a few weeks ago. Here is an article from USA TODAY from last year