This was a fact. The crime rate did drop by 18%. However, the rate that dropped by 18% was not the number of crimes actually committed in fact, during the experiment, Washington's weekly murder count hit the highest level ever recorded. The 18% drop was from Hagelin's computer prediction of what would have happened had his meditators not been meditating and levitating.
http://www.guardian.co.uk/education/2012/oct/08/meditation-crime-prevention-research