Forensik : Sidik Jari, DNA, Kematian

A forensic investigator finds a partial fingerprint at a crime scene. The print shows a loop pattern with 12 ridge counts. Which classification system would best help identify this print, and what additional information would be needed to make a positive match to a suspect?

• AFIS Database

• Galton's Classification

• Henry Classification System

• Bertillon System

Two fingerprints are being compared in court. The defense argues that a 10-point match is insufficient for identification. Based on your understanding of fingerprint analysis, evaluate whether the number of matching ridge characteristics alone determines the validity of a fingerprint match.

• No, the number of matching ridge characteristics alone does not determine the validity of a fingerprint match.

• The number of matches is the only factor in fingerprint analysis.

• Yes, matching ridge characteristics alone are sufficient for identification.

• A 10-point match is always conclusive for identification.

A latent fingerprint is found on a dark, wet surface. Which development technique — ninhydrin, cyanoacrylate fuming, or magnetic powder — would be most effective, and why does the surface condition influence your choice?

• Ninhydrin

• Magnetic powder

• Water-based spray

• Cyanoacrylate fuming

A DNA sample collected from a crime scene is degraded due to environmental exposure. How would this affect the reliability of a Short Tandem Repeat (STR) analysis, and what alternative DNA profiling method could forensic scientists use?

• Protein profiling techniques

• Nuclear DNA (nDNA) analysis

• Mitochondrial DNA (mtDNA) analysis

• RNA sequencing methods

Two suspects share 50% of their DNA with the victim. Explain how forensic scientists use DNA profiling to distinguish between a parent-child relationship and a sibling relationship when analyzing crime scene evidence.

• Forensic scientists analyze mitochondrial DNA to differentiate between cousins and siblings.

• DNA profiling can only determine if two suspects are related by comparing their eye color.

• Forensic scientists use DNA profiling to distinguish parent-child from sibling relationships by analyzing specific DNA markers (STRs) and their inheritance patterns.

• Forensic scientists use DNA profiling to identify the victim's relatives based on blood type analysis.

A forensic lab receives blood and saliva samples from the same suspect. Both samples produce different DNA profiles. What scientific explanation could account for this discrepancy, and how might it impact the court case?

• Different DNA profiles may arise from lab errors or sample mishandling.

• DNA profiles can vary due to environmental factors or time decay.

• Different DNA profiles may result from contamination, chimerism, or mixed samples.

• Different profiles might be due to unrelated genetic ancestry or mutations.

A blood sample at a crime scene has been exposed to sunlight for 48 hours. How would this affect the ability to determine the ABO blood type and extract a usable DNA profile? Which component of blood degrades faster and why?

• ABO blood type determination is unaffected, while DNA extraction is impossible due to degradation of plasma.

• The ABO blood type can be determined accurately, and DNA extraction is unaffected. White blood cells degrade faster due to sunlight exposure.

• The ability to determine the ABO blood type would be compromised, while DNA extraction may still be possible but less reliable. Red blood cells degrade faster due to environmental exposure.

• Both ABO blood type and DNA extraction remain reliable, with no degradation of blood components.

Investigators find a bloodstain pattern that shows a circular shape with scalloped edges. What does this pattern suggest about the height from which the blood fell, and how can the angle of impact be calculated using the stain's shape?

• The blood fell from a low surface, and the angle of impact is irrelevant to the stain's shape.

• The blood fell from a moving object, and the angle of impact can be inferred from the stain's texture.

• The blood fell from a great distance, and the angle of impact is determined by the stain's color.

• The blood fell from a height, and the angle of impact can be calculated using the stain's width and length.

A forensic pathologist must determine whether a victim's death was caused by drowning or by strangulation before being placed in water. Describe two specific forensic indicators that would help differentiate between these two causes of death.

• Presence of water in the lungs indicates drowning; signs of neck trauma or petechial hemorrhages indicate strangulation.

• Presence of bruising on the arms suggests drowning; signs of broken ribs indicate strangulation.

• Absence of water in the stomach indicates drowning; signs of facial swelling indicate strangulation.

• Presence of foam in the mouth indicates drowning; signs of lacerations on the neck indicate strangulation.

A body is found with full rigor mortis and early signs of livor mortis that have not yet fixed. Using your knowledge of postmortem changes, estimate the approximate time since death and explain the biological processes behind each observation.

• Approximately 24 to 30 hours since death.

• Approximately 6 to 8 hours since death.

• Approximately 1 to 2 hours since death.

• Approximately 12 to 18 hours since death.