What type of evidence is used to link a suspect to a crime through DNA?

Biological evidence is pivotal in linking a suspect to a crime through DNA. This type of evidence includes any biological material that can contain DNA, such as blood, saliva, hair, skin cells, or any other bodily fluids. DNA is unique to each individual (with the exception of identical twins), making it a powerful tool for forensic investigators. When biological evidence is collected from a crime scene, forensic scientists can analyze the DNA profiles and compare them with samples from suspects or databases, establishing a direct connection between the suspect and the crime scene.

Circumstantial evidence, while important in criminal investigations, relies on inference to suggest a link rather than direct physical proof, which doesn't apply to the definitive nature of DNA analysis. Physical evidence encompasses tangible items like weapons or fingerprints that may assist in an investigation but do not specifically pertain to DNA. Digital evidence, while increasingly relevant in investigations, includes data from electronic devices and does not directly correlate with biological evidence in terms of DNA linkage. Thus, biological evidence stands out as the most applicable for identifying suspects through their genetic material.