Question and Answer in Forensic Sciences
Through case review, a forensic expert can provide a critical technical assessment and, when necessary, conduct in-depth evaluation in collaboration with other experts to determine the following:
- Whether proper procedures and methodologies were followed
- Whether the reported results are accurate and not overstated
- Whether errors may have occurred
- Whether all examinations were conducted correctly and comprehensively
- Strengths and weaknesses of the case
- Recommendations for further investigations or examinations
- Recommendations for involving additional experts
- Recommendations on the best way to present forensic evidence
Generally, the following documents should be available:
- Crime scene / incident reports
- Investigation reports
- Statements of witnesses and suspects
- Photographs and videos from the crime scene / incident
- Police, emergency services, civil defense, hospital, and forensic pathology reports
- A list of all evidence related to the case
- Forensic laboratory reports
- Chain of custody documentation forms
The chain of custody is often considered the weakest link in criminal investigations. It refers to the continuous and precise documentation of evidence to establish its connection to a specific crime. Physical evidence plays a critical role among all investigative information sources (such as confessions, statements, and video surveillance). Even carefully collected and preserved evidence can lose its legal value if the chain of custody is not properly maintained. Therefore, it is essential to ensure traceability and continuity of evidence from the crime scene to the courtroom.
Comparison of physical evidence involves linking physical traces—if suitable for comparison—to a suspected source. The outcomes of comparison may include exclusion, similarity, or inconclusive results.
Interpretation of physical evidence involves explaining the presence of physical traces in relation to time, location, and events, and assessing their consistency with testimonial evidence.
Crime scene reconstruction uses scientific methodology, physical evidence, deductive reasoning, and their interrelationships to formulate hypotheses about the sequence of events surrounding a crime. It seeks to answer: What happened? and How did it happen?
Crime scene reenactment involves the presence of the victim, suspect, witness, or others to recreate the event(s) that produced the crime scene or physical evidence based on their knowledge of the incident.