▁fall ▁of ▁ 1 9 ▁per ▁cent ▁in ▁hom ic ides ▁since ▁ 2 0 0 1 / 0 2 ", ▁as ▁measured ▁by ▁The ▁Hom ic ide ▁Index . ▁ ▁United ▁States ▁ ▁There ▁are ▁two ▁main ▁crime ▁databases ▁maintained ▁by ▁the ▁United ▁States ▁Department ▁of ▁Justice ▁( DO J ): ▁the ▁Bureau ▁of ▁Justice ▁Statistics ' ▁National ▁Crime ▁Vict im ization ▁Survey ▁( N CV S ) ▁and ▁the ▁Federal ▁Bureau ▁of ▁Investig ation ' s ▁Un iform ▁Crime ▁Report ▁( U CR ). ▁Non - f atal ▁violence ▁is ▁reported ▁in ▁the ▁N CV S , ▁which ▁measures ▁ra pe ▁and ▁sexual ▁assault , ▁rob ber y , ▁and ▁ag gra v ated ▁and ▁simple ▁assault ▁reported ▁by ▁households ▁survey ed ▁by ▁the ▁U . S . ▁Census ▁Bureau . ▁The ▁U CR ▁tracks ▁similar ▁non - f atal ▁violence , ▁plus ▁murder ▁and ▁non - neg lig ent ▁m ans la ugh ter ▁recorded ▁by ▁law ▁enfor cement . ▁ ▁There ▁are ▁significant ▁method ological ▁and ▁defin itional ▁differences ▁between ▁the ▁N CV S ▁and ▁U CR : ▁The ▁N CV S ▁includes ▁estimates ▁of ▁both ▁reported ▁and ▁un report ed ▁cr imes , ▁while ▁the ▁U CR ▁collect s ▁data ▁on ▁cr imes ▁recorded ▁by ▁the ▁police . ▁The ▁U CR ▁includes ▁hom ic ide , ▁ar son , ▁and ▁commercial ▁cr imes , ▁while ▁the ▁N CV S ▁does ▁not . ▁The ▁U CR ▁ex cludes ▁simple ▁assault ▁( att acks ▁or ▁attempted ▁attacks ▁without ▁a ▁weapon