▁the ▁kn ife ▁in ▁the ▁evidence ▁room ▁is ▁the ▁same ▁kn ife ▁found ▁at ▁the ▁crime ▁scene . ▁However , ▁if ▁there ▁are ▁dis cre pan cies ▁and ▁it ▁cannot ▁be ▁proven ▁who ▁had ▁the ▁kn ife ▁at ▁a ▁particular ▁point ▁in ▁time , ▁then ▁the ▁chain ▁of ▁cust ody ▁is ▁broken ▁and ▁the ▁def endant ▁can ▁ask ▁to ▁have ▁the ▁resulting ▁evidence ▁declared ▁in ad miss ible . ▁ ▁Ch ain ▁of ▁C ust ody ▁is ▁also ▁used ▁in ▁most ▁chemical ▁sampling ▁situations ▁to ▁maintain ▁the ▁integrity ▁of ▁the ▁sample ▁by ▁providing ▁documentation ▁of ▁the ▁control , ▁transfer , ▁and ▁analysis ▁of ▁samples . ▁Ch ain ▁of ▁cust ody ▁is ▁especially ▁important ▁in ▁environmental ▁work ▁where ▁sampling ▁can ▁identify ▁the ▁existence ▁of ▁cont am ination ▁and ▁can ▁be ▁used ▁to ▁identify ▁the ▁responsible ▁party . ▁ ▁See ▁also ▁Ev idence ▁bag ▁ ▁Ev idence ▁management ▁ ▁Pro ven ance ▁ ▁Trace ability ▁ ▁External ▁links ▁ ▁Federal ▁R ules ▁of ▁Ev idence ▁Rule ▁ 9 0 1 ▁( Authentication ▁and ▁Ident ification ▁Rule ▁used ▁for ▁Ch ain ▁of ▁C ust ody ) ▁ ▁Non ▁Federal ▁Ch ain ▁of ▁C ust ody ▁ ▁Category : C riminal ▁justice ▁eth ics ▁Category : E v idence ▁law <0x0A> </s> ▁Crist ian ▁Pa ț ur c ă ▁( 1 0 ▁September ▁ 1 9 6 4 ▁– ▁ 1 8 ▁January ▁ 2 0 1 1 ) ▁was ▁a ▁Roman ian ▁composer . ▁ ▁Pa ț ur c ă ▁was ▁born ▁and ▁died ▁in ▁Buch