..About the article..• Almost naked and decomposed body of a young Asian women was found hidden in a suitcase.• She had been suffocated.• Her name was Hyo Jung Jin, 21 years old and was studying French at the University of Lyon.• She did not return to university in October after a trip to London.• The police linked Hyo Jung Jin’s death to that of In Hea Song, whose almost naked body was found in a cupboard in a house in East London.• The house that being visited by Hyo Jung Jin and the body of In Hea Song founded belong to the same landlord.• Tape used by the murder to bind around Hyo Jung Jin face and body was the same tape found out at Kyo Soo Kim’s house and has Kyo Soo Kim’s blood found on it.
• Matched blue paint from a bedroom and paint at the suitcase hiding Hyo Jung Jin’ body.• Blood found at all over Kyo Soo Kim’s room.• Mobile phone recorded trace Kim Soo Kim at the same place as the Hyo Jung Jin’s body dump.• Toronto : orange paint found on the t-shirt and the tape used around In Hea Song’s wrist.• Further DNA test confirmed that both body found in the same cupboard.
..Idea..• The murder is the same person because the way of the murderer look similar.• Kyo Soo Kim is a suspect.• Further evidence founded support the assumption that the suspect is the murder.• The polices investigate more further.
..Learning Issues..• How the investigator can relate both murder cases to each other?• What is the process needed to be used by using DNA in order to identify the body?• What are the evidences can be related between Kyo Soo Kim and the murderer?
..Technique to process evidence.. Paint Analysis Polymerase Chain Reaction Gel electrophoresis
Paint Analysis• A specialized technique called pyrolysis gas chromatography might be used to determine its composition.• Pyrolysis involves heating the sample until it turns into a vapor.• This is then injected into a gas chromatograph that separates the components.• These can be identified by molecular weight using mass spectrometry, which creates a chemical fingerprint that can be compared to reference samples.
Polymerase Chain Reaction• With PCR, any specific segment one target sequence within a DNA sample can be copied many times (amplified) completely in vitro.• Require double-stranded DNA containing the target sequence, a heat- resistant DNA polymerase, all four nucleotide two 15 to 20-nucleotide DNA strand that serve as primers. One primer is complementary to one end of the target sequence on one trand, the second primer is complementary to the other end of the sequence on the other strand.
• First step is denaturation : the reaction mixture is heated to denature ( separate ) the DNA strands.• Second, coal to allow primers to form hydrogen bonds with ends of target sequence.• Then, extension DNA polymerase add nucleotide to 3’end of each primer.• Repeat the PCR.
Gel electrophoresis• Gel electrophoresis is used for separating nucleic acid or protein that differ in size, electrical charge or other physical properties.• DNA molecules are separated by gel electrophoresis in restriction fragment analysis of both cloned gene and genomic DNA.• Technique : gel electrophoresis separate macromolecule on the basis of their rate of movement through a polymeric gel in an electric field.• Each sample, a mixture of DNA molecule is placed in a separate well near one end of a thin slab of gel. The gel is set into a small plastic support and immersed in an aqueous solution in a tray with electrode at each end.
• When the current is turned on, the negatively charged DNA molecule move toward the positive electrode with shorter molecule moving faster than longer one.• Bands are shown here in blue but on an actual gel, the bands would not be visible at this time.• The blue paint from the bedroom at Kyo Soo Kim house matched to the blue paint on the suitcase Hyo Jung Jin’s body was found.
Conclusion• During the investigation, all the evidence pointed to the suspect, Kyo Soo Kim.• So, in 2003, the judge found Kyo Soo Kim guilty for the two murders and gave him a life sentence.