DNA Evidence and Analysis Techniques

DNA Evidence

• Definition: DNA (Deoxyribonucleic acid) is a unique genetic material found in every cell of an individual's body.
• Types of DNA evidence:
  • Nuclear DNA: found in the nucleus of cells, used for identifying individuals.
  • Mitochondrial DNA: found in the mitochondria, used for identifying maternal lineage.
• Collection methods:
  • Blood, saliva, skin cells, and other bodily fluids.
  • Evidence from crime scenes, such as hair, semen, and tissue.
• Analysis techniques:
  • PCR (Polymerase Chain Reaction): amplifies DNA samples.
  • RFLP (Restriction Fragment Length Polymorphism): analyzes DNA fragments.
  • STR (Short Tandem Repeat): analyzes repetitive DNA sequences.
• Uses in criminology:
  • Identifying suspects and linking them to crime scenes.
  • Excluding individuals from suspicion.
  • Solving cold cases.

Serological Evidence

• Definition: Serological evidence refers to the analysis of bodily fluids, such as blood, semen, and saliva, to identify individuals and determine their involvement in a crime.
• Types of serological evidence:
  • Bloodstains: analyzed for DNA, blood type, and other characteristics.
  • Semen: analyzed for DNA and other characteristics.
  • Saliva: analyzed for DNA and other characteristics.
• Collection methods:
  • Swabbing surfaces and objects.
  • Collecting liquid samples.
• Analysis techniques:
  • ABO blood typing: determines an individual's blood type.
  • Enzyme typing: analyzes enzymes in bodily fluids.
  • DNA analysis: uses techniques such as PCR and STR.
• Uses in criminology:
  • Identifying suspects and linking them to crime scenes.
  • Determining the sequence of events at a crime scene.
  • Providing evidence in court proceedings.

DNA Evidence

• DNA is a unique genetic material found in every cell of an individual's body.

Types of DNA

• Nuclear DNA: found in the nucleus of cells, used for identifying individuals.
• Mitochondrial DNA: found in the mitochondria, used for identifying maternal lineage.

Collection of DNA Evidence

• Blood, saliva, skin cells, and other bodily fluids.
• Evidence from crime scenes, such as hair, semen, and tissue.

DNA Analysis Techniques

• PCR (Polymerase Chain Reaction): amplifies DNA samples.
• RFLP (Restriction Fragment Length Polymorphism): analyzes DNA fragments.
• STR (Short Tandem Repeat): analyzes repetitive DNA sequences.

Uses of DNA Evidence in Criminology

• Identifying suspects and linking them to crime scenes.
• Excluding individuals from suspicion.
• Solving cold cases.

Serological Evidence

• Refers to the analysis of bodily fluids to identify individuals and determine their involvement in a crime.

Types of Serological Evidence

• Bloodstains: analyzed for DNA, blood type, and other characteristics.
• Semen: analyzed for DNA and other characteristics.
• Saliva: analyzed for DNA and other characteristics.

Collection of Serological Evidence

• Swabbing surfaces and objects.
• Collecting liquid samples.

Analysis of Serological Evidence

• ABO blood typing: determines an individual's blood type.
• Enzyme typing: analyzes enzymes in bodily fluids.
• DNA analysis: uses techniques such as PCR and STR.

Uses of Serological Evidence in Criminology

• Identifying suspects and linking them to crime scenes.
• Determining the sequence of events at a crime scene.
• Providing evidence in court proceedings.