What is a potential use of trace materials in an investigation?

Trace materials serve as critical evidence in investigations by connecting a suspect to a crime scene or a victim. This type of evidence often includes residues or small fragments that can be found on clothing, personal belongings, or surfaces at a crime scene. It can encompass a wide variety of substances, like hair, fibers, gunshot residue, or paint chips.

When investigators analyze these trace materials, they can establish a link between the suspect and the location of the crime or the victim, strengthening the case against the suspect. The presence of such materials can place a suspect at a crime scene or indicate involvement in a criminal act, significantly aiding in the investigative process.

In contrast, trying to determine a suspect's financial motive or identifying their demographic characteristics does not rely on physical evidence but rather on the suspect's background or behaviors. Similarly, establishing alibis for witnesses would depend on testimonies and verification of activities rather than trace materials. Thus, linking a suspect to a crime through small evidence stands out as the primary function of trace materials in criminal investigations.