Final answer:
A detective can connect a crime scene to a suspect or victim using DNA evidence, which involves matching DNA sequences found at the scene with the suspect. Eyewitness identification can be unreliable, making DNA evidence crucial. A child's DNA fingerprint must match the genetic markers of the parents to establish a relationship.
Step-by-step explanation:
Identification that will allow a detective to connect the crime scene to the suspect or victim typically involves DNA evidence. Technicians use similarities in DNA sequences to establish connections between individuals and a crime scene. For instance, forensic geneticists can compare human tissue samples from the crime scene, such as blood or skin cells, with the suspect's DNA to find an exact match. This kind of evidence is critical because even though detectives are not present at crime scenes, like chemists in a laboratory, they collect evidence to piece together what happened based on the properties they can observe.
The reliability of eyewitness identification can be questionable, as demonstrated in the case of Jennifer Thompson, which highlighted the potential issues with eyewitness misidentification and how it can lead to wrongful convictions. Faulty eyewitness identification is the leading cause of wrongful convictions, emphasizing the importance of DNA evidence in criminal investigations.
To establish a familial relationship, such as paternity, a child's DNA fingerprint should contain genetic markers that closely match those of the alleged father. If the mother's identity is also in question, the child's DNA must have matching markers with the alleged mother as well. This process was notably used when Dr. Alec Jeffreys invented DNA fingerprinting, providing a solution to an immigration case by proving a familial relationship.