Minozzi and her colleagues detailed their argument in the May issue of the Journal of Forensic Sciences.

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The 1995 study, in the Journal of Forensic Sciences, looked at proficiency tests labs take to see whether their work is sound.

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Adam Negrusz, an associate professor of forensic sciences at the University of Illinois at Chicago, said he isn't worried about the cleanliness of money in terms of public health.

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