What is forensic 'identification' of physical evidence?

What is forensic 'identification' of physical evidence?

Identification is what it is. What is a powder? Is it a drug that contains heroin, or is it a drug that contains cocaine? The ultimate result of the identification is the exclusion of all other substances but one. When a forensic scientist goes to court with the result of an analysis of a white powder and reports to the court, for example, that that white powder contains heroin, that forensic examiner will be as certain as to his or her findings and to the identity of his or her findings as modern technology will allow one to be. It must be a near absolute identification and exclude all other substances from consideration.