Well, statistics are not perfect, but that does not mean that you can negate their findings entirely. It would be impossible to get an absolutely accurate statistic, but that doesn't mean what they do say (when taken from a reliable source) cannot provide us with some truth.

I would like to say that the servicemen/cop statistic is in all likelihood much higher than the one reported, because people are reluctant to report an officer to another officer, etc.

It makes the news because these are people who are supposed to protect us, not abuse us.