You appear to be a conspiracy theorist. Good luck with that.
Why nobody bothered to include the murders in the published FBI 2012 crime data is hard to explain, except perhaps they were all to busy meeting with Bloomberg to plan their anti-gun crusade.
Take a look at the number of murders reported for Newtown Connecticut in 2012 on the FBI.gov website:
FBI 2012 CT Reported Crimes by Town
It is not surprising that some people mistakenly believe the published FBI data, or are otherwise skeptical of anything the government says given the reputation of the current administration and liberals in general for lying for political reasons.