Although, in our lab report, suspect ones DNA matched the crime scene when cut with enzyme one, this can be explained by how closely related the two suspects are. Therefore two enzymes were used to cut the DNA; the suspect has to match both. Moreover, the limitation to DNA fingerprinting is, if a person were to have an identical twin. This is because identical twins have the same DNA because they come from the same egg. If a suspect’s DNA matched that of the one being tested, and they had an identical twin, a farther investigation would need to be done.
Statement of the Problem DNA has become a vital part of criminal investigations. DNA can include and exclude suspects of criminal investigations. During a criminal investigation, all DNA should be collected, properly preserved and tested, but at times this does not occur or the technology was not available for this process to occur. In addition, DNA has become an imperative portion of exoneration cases.
One of the most accurate methods of connecting a suspect with a crime is through the use of DNA analysis. Even if no fingerprints are left behind at a robbery, for instance, a single strand of hair or skin cell from the thief can be used to positively identify a suspect. Conversely, if a suspect’s DNA does not match samples procured from a crime scene, the use of so-called “genetic fingerprinting” can exonerate, or clear, them. Concern over the issue of wrongful convictions, coupled with a sense of greater trust in DNA analysis over other, more conventional methods of prosecution, such as eyewitness testimony, has led some to call for mandatory DNA testing before any person begins serving a sentence for a serious crime, as well as
Case #1: 1977 Murder of James Anagnos Victims: James Anagnos Suspects: Frank Wright How hair played a role in solving the case: The hair of Frank Wright was found clenched in the victim, James Anagnos, hand due to an earlier conflict between the two. Case #2: The murder of Elizabeth Ballard Victims: Elizabeth Ballard Suspects: Two unnamed men How hair played a role in solving the case: Follicles of both victims dogs were found at the initial place of the murder, directly linking them to the death. Case #3: The Disappearance of Melissa Brannen Victims: Melissa Brannen Suspects: Caleb Hughes How fibers played a role in solving the case: The fibers found in the backseat of Hughes car were similar to those on the outfit
Blood was also found on a pair of socks located in Simpson’s closet (“O.J. Simpson Civil Trial”). Following several tests, the results showed that DNA matching Simpson and Nicole’s. The prosecution deemed this a direction link to Simpson and the victims. However, the defense once again believed the socks were placed by the police. They stressed the point that the blood was soaked through the sock from one side to another.
The police department narrow down the investigation to four suspects Bob Whitney, Mary Lynn Turner, Joe Rangel and Allen Dann. They all provide a blood sample to the investigation to determine if one of the blood samples belongs to the suspect. A new development happened during our investigation, where information about a missing girl surface name Sarah Hopewell reflecting she could be the victim in the crime. Based on Sarah medical records we determine she was blood type B negative (Rh-), Caucasian and twenty-one years of age when she disappear. The question we are trying to answer during our investiagation “Do the skeletal remains belong to Sarah Hopewell?”
The two story traditional Victorian house exploded and engulfed in flames to eliminate evidence. After the charred bodies were recovered from the fire, tissue samples were obtained to identify each victim, using DNA, which is the molecule responsible for transmitting all hereditary information passed on from one generation to the next (Johll pg. 409, 2007). To determine the cause of death, an autopsy was performed and tissue samples from each victim. Among the evidence recovered after the fire was a single syringe, which was fully intact and sent for analysis.
Hair, like fingerprints can tell us if there was another person involved,the sex,raics, and sometimes the age. On the corner of the table was hair, it was determined to belong to Anna. Also found at the crime scene were pills next to anna. After analyzing the pill we found that they were acetylsalicylic acid AKA aspirin. lastly there was a muddy shoe print found.
Untested Victims Bailey Votto 4/19/16 Margaret Oakes Paper 4 Draft #2 When the two solutions, sodium chloride (NaCl) and silver nitrate (AgNO3) react, a soluble sodium nitrate (NaNO3) and a precipitate silver chloride (AgCl) form. While this reaction is not a common occurrence for most of us in our daily life and work, it is in a forensic science lab. This chemical reaction is just one of the many techniques used to unveil fingerprints in a crime scene. Unfortunately, fingerprints are not always left or able to be found. In that case, new chemical procedures must take place.
DNA in Forensic Science DNA is the carrier of genetic information in humans and other living organisms. It has become a very useful tool in forensic science since it was discovered. In forensic science, DNA testing is used to compare the genetic structure of two individuals to establish whether there is a genetic relationship between them. One example of the use of DNA in forensic science that is important in biology today is comparing a suspect’s DNA profile to DNA that was discovered at a crime scene.
More than 75% of cases that have used DNA to exonerate have involved misidentification by the eyewitnesses (“Credible Eyewitnesses”). This proves that eyewitnesses are not reliable sources in a trial. According to the article “Credible Eyewitnesses”,
Later on DNA was taken from close relatives of Hanratty and experts stated the fact that the odds of 2.5 million/1 against the killer being a close relative. Personally I believe the DNA and the evidence where highly contaminated. The evidence samples from the crime scene were both stored nearby to each other, which can lead to contamination. The samples have been stored in unsealed paper envelopes, which were often removed at the same time that clothing of Valarie and the handkerchief. This can lead to contamination as both evidence samples have been in direct contact with James Hanratty’s clothing.
Have you ever wonder how does a crime scene investigator, known as a CSI, discover blood spatter on different fabrics, which is not visible to the human eye? The key is bluestar. According to the article “Influence of Bluestar Reagent on Blood Spatter Stain of Different Fabrics” by Arnon Grafit, bluestar is a “luminol-based reagent that is applied by spraying on surface.” Not only that, but “it helps obtain DNA and to analyze spatters patterns. By analyzing the article the reader is able to understand how bluestar works through the rhetorical techniques used.