So,if a murder took place in Los Angeles and a suspect claimed to have been in SanDiego all the time, hair analysis could not help, because the cities havesimilar isotope signatures.

• 所以说如果一个嫌犯在洛杉矶作案但他声称自己一直在圣地亚哥，毛发分析就无能为力了，因为这两个城市具有类似的同位素特征。