Which type of evidence is used to genetically link a suspect to a crime by analyzing biological material such as blood or DNA?

• A. Forensic anthropology
• B. Toxicology
• C. Trace evidence
• D. DNA evidence

Answer: (D)

DNA analysis is the method used to genetically link a suspect to a crime by examining biological material such as blood. Because DNA is unique to each individual (except identical twins), comparing DNA from a crime-scene sample to a suspect’s DNA can either include or exclude the person as the source of the biological material. The process typically involves extracting the DNA, amplifying it, and generating a profile at specific genetic loci (often short tandem repeats). A match indicates a very high probability that the same person contributed both samples, with significance quantified through statistical measures and database searches like CODIS.

Context helps: while a strong DNA match is highly persuasive, interpretation also depends on sample quality, potential mixtures of DNA from multiple people, contamination risks, and maintaining a proper chain of custody. This makes DNA evidence powerful for genetic linking but not infallible on its own.

Other options don’t fit as the primary means of genetic linking. Forensic anthropology deals with identifying remains and analyzing bones, not DNA matching. Toxicology looks for chemicals and substances, not genetic material. Trace evidence is a broad category of small physical materials (like fibers or glass) and, while it can include DNA, is not defined by genetic linkage.