What is the purpose of analyzing substances in a crime lab's chemistry section?

Analyzing substances in a crime lab's chemistry section is primarily focused on determining the presence or absence of controlled substances. This is crucial in criminal investigations, particularly in cases involving drug-related offenses. The forensic chemists use various analytical techniques to identify specific compounds and substances, which can provide evidence supporting the prosecution or defense in court. Confirming the presence of illegal substances not only helps in establishing elements of a crime but also aids in understanding the circumstances surrounding an offense.

While determining the origin of a substance, comparing with suspect's records, or confirming eyewitness accounts may also be important aspects of an investigation, they fall outside the primary function of the chemistry section, which is specifically geared towards the analysis of substances for their chemical properties and classifications. Thus, the emphasis remains on identifying controlled substances, making this the most relevant purpose within the context of crime lab operations.