Question

how can dna be used to help solve a crime?

Explanation:

DNA is unique to each individual (except identical twins). Crime scene DNA (e.g., from blood, hair) can be collected. It is analyzed (e.g., through STR analysis). Then compared to DNA databases (e.g., CODIS) or suspects' DNA. If a match is found, it can link a suspect to the crime scene.

Answer:

DNA from a crime scene (e.g., blood, hair, saliva) is collected. It undergoes analysis (like STR - Short Tandem Repeat analysis). This analyzed DNA profile is compared to DNA profiles in databases (such as CODIS in the US) or to DNA samples taken from suspects. A match can place a suspect at the crime scene, helping solve the crime by providing evidence of their presence.