dna presentation
Crime scene investigation
In this project, the Crime Scene Investigation project we have been exploring the forensic sciences and how they are related to our justice system. We started out by discussing what exoneration is. Exoneration is the act of freeing somebody from conviction and/or blame of a crime. We also learned that exoneration is possible for anyone with the right evidence. A guest speaker also came named Ken Marsh. Ken was a man who spent nearly 2 decades in prison for a crime he did not commit. Forensic Science has also greatly affected the justice system because many people who were originally found guilty have been re-tried and found innocent due to forensic evidence. Also, when new crimes take place, we now go through a much more detailed process before we determine someone's involvement in the crime. For this project, my partner was Lauren Brown. We started this project by being presented with a crime scene on September 22, 2014. We investigated this same crime scene for about 2 weeks. The crime scene was laid out as if it were in a dining room. The report said that at approximately 1:35AM there was a gunshot heard and Aaron Lee was found shot dead at his dining room table. The 2 prime suspects were Michelle Lee (Aaron's wife) and Scott Henderson (his stepson). The table was strewn with all kinds of things including various liquor bottles, an empty bottle of oxycodone, and some pieces of paper. The papers included an eviction notice and an IRS letter. The main part of this project was that we had to write several report on the different aspects of forensic sciences. I wrote about Trajectory of a Bullet, Iodine Fuming, Toxicology and Nuclear DNA.
The first science that I learned about was Trajectory of a bullet. This is import in the act of solving crimes because knowing the angle at which someone was shot can be important in knowing whether the shooting was a murder or a suicide. The next report that I wrote was on Iodine Fuming. this is the other method besides superglue fuming used to identify fingerprints. This method however, is only used on paper products. The third report that I completed was about toxicology. Toxicology was interesting because this process allows you to see what types of chemicals and substances are in the victims body. Aaron had alcohol and oxycodone in his blood system. The final science that I explored was Nuclear DNA. This was very interesting because it links evidence from the crime scene directly to a person. This process can be of huge importance to solve a crime. The blood spatter report, which Lauren was responsible for helped us to solve this case because some of the blood found at the crime scene matched blood found in Scott Henderson's sink. We also used other sciences to solve other aspects of the crime.
The forensic science that I studied that was the most interesting to me was Toxicology. I enjoyed this certain science because it involved medical science along with crime scene investigations. For this science you have to withdraw fluids from the victim and/or suspects because this allows us to test the different counter-substances that are in the people that are involved. During this project, I think that I was good at using my time wisely and consistently and I also think that I improved my technical writing skills. One thing that I could have done better during this project was to be more involved in my actual research and investigation. I think I was somewhat lacking when it came to marking and exploring the crime scene and wish I would have done better. Overall, this project was a good introduction into the world of Crime Scene Investigation and I enjoyed participating in this project.
The first science that I learned about was Trajectory of a bullet. This is import in the act of solving crimes because knowing the angle at which someone was shot can be important in knowing whether the shooting was a murder or a suicide. The next report that I wrote was on Iodine Fuming. this is the other method besides superglue fuming used to identify fingerprints. This method however, is only used on paper products. The third report that I completed was about toxicology. Toxicology was interesting because this process allows you to see what types of chemicals and substances are in the victims body. Aaron had alcohol and oxycodone in his blood system. The final science that I explored was Nuclear DNA. This was very interesting because it links evidence from the crime scene directly to a person. This process can be of huge importance to solve a crime. The blood spatter report, which Lauren was responsible for helped us to solve this case because some of the blood found at the crime scene matched blood found in Scott Henderson's sink. We also used other sciences to solve other aspects of the crime.
The forensic science that I studied that was the most interesting to me was Toxicology. I enjoyed this certain science because it involved medical science along with crime scene investigations. For this science you have to withdraw fluids from the victim and/or suspects because this allows us to test the different counter-substances that are in the people that are involved. During this project, I think that I was good at using my time wisely and consistently and I also think that I improved my technical writing skills. One thing that I could have done better during this project was to be more involved in my actual research and investigation. I think I was somewhat lacking when it came to marking and exploring the crime scene and wish I would have done better. Overall, this project was a good introduction into the world of Crime Scene Investigation and I enjoyed participating in this project.
Toxicology
Grace Wolf-Cartier
Crime Scene: #1
Evidence Being Examined: The Victim’s Body
Forensic Science Used: Toxicology
Toxicology is the study of abnormal or foreign bodies in a living organism. Forensic science uses toxicology to determine if the victim was poisoned, was under the influence of drugs and possibly the cause of death. Throughout history poisoning has been a common method of murder. This is partly because many substances can be poisonous and partly because poisoning leads doctors to believe that there is a medical explanation. Poisons detected through toxicology can range from carbon monoxide to standard medication mixtures. Accidental deaths can also be caused by medicine such as Atropine or Thallium. Atropine is a poisonous substance found in some plant but when used medically, it is used as a muscle relaxant. Thallium is a chemical element with very poisonous compounds. However, toxicology does not only cover poisons, it can also be helpful in finding foreign substances in the body that may be harmful such as, alcohol, illegal drugs, or industrial chemicals. This piece is connected to the case because evidence shows that Aaron Lee had been drinking the night of the accident. There could also be evidence from this test whether he was using or forced to use drugs. The first person to discover the idea of a chemical process for discovering poison was Dr. Hermann Boerhaave. His testing method was very simple; testing the different smells of poisons. Since then, toxicology has been a more complicated and much more accurate process.
Toxicology is a known as a control sample. This means a sample that was collected and is analyzed to further research the crime. This is because it is evidence collected biologically. It has been tested through blood, hair, saliva or other bodily products. Toxicology in forensics can be used in many ways such as proving a DUI or furthering research on a murder. Although poisoning isn’t the most common way of killing people anymore, there is still a combined average of 3,070,000 people dying each year from drugs and alcohol. Blood samples are the most common way to collect toxicology reports. Urine is used frequently as well, for it’s ability to hold drug substances longer than blood. This makes it more clear what the substances being used were and how much of it there was. Toxicologists must also perform post-mortem exams and collect samples to test them. These exams can also be achieved at the request of someone. Any of these steps can lead to decisions on whether it was forced or self-implicated; enough to kill them or not.
One main process of toxicology is called gas-liquid chromatography. Chromatography is a laboratory process of separating different mixtures. Gas chromatography is done by using a chromatograph machine in order to mechanically separate mixtures and chemicals. The first step in this process is to collect the mixture(s) that need to be tested. Always make sure to have clean and sanitary tools during this process as this can affect results. Insert the syringe into a chamber to test the materials in a gas substance. The liquid samples are then vaporized. The materials with more interaction with the machine then separate from those with less. Gas streams are analyzed every so often and then at the end of the machine’s process the separated materials can be determined and analyzed further.
Chromatography is the main method that forensic scientists use in toxicology and they’re many other methods, however during an autopsy scientists can use different approaches in gathering samples from patients. Whether this be blood, saliva, hair, or urine. Gas-liquid chromatography is the most effective approach to finding evidence from forensic toxicology.
One of the main advancements in forensic toxicology has been the upgrade of laboratory practices. Laboratory practices are extremely important in all kinds of science, not just forensics. This is because having good lab methods is the only way to be sure of the accuracy of your testing. There have also been advancements in the machines used for toxicology. The machines have become more precise and available for more types of testing.
Aaron Lee tested positive for Opioids, Oxycodone, Alcohol, and Ethanol. The alcohol was obvious during this investigation because there were liquor bottles spread over the crime scene. Aaron had very clearly been drinking around the time of the death. His wife had also been prescribed a bottle of oxycodone for reasons unknown and the bottle had his fingerprints on it. These pieces of evidence are all a contribution the solving of this crime and will lead the investigation further.
http://www.crimelibrary.com/criminal_mind/forensics/toxicology/2.html
http://abft.org/files/WHAT%20IS%20FORENSIC%20TOXICOLOGY.pdf
http://emedicine.medscape.com/article/1680257-overview
http://en.wikipedia.org/wiki/Forensic_toxicology#Gas_chromatography
http://www.chemguide.co.uk/analysis/chromatography/gas.html
http://en.wikipedia.org/wiki/Gas_chromatography#Methods
http://www.chemguide.co.uk/analysis/chromatography/gas.html
http://hiq.linde-gas.com/en/analytical_methods/gas_chromatography/index.html
Crime Scene: #1
Evidence Being Examined: The Victim’s Body
Forensic Science Used: Toxicology
Toxicology is the study of abnormal or foreign bodies in a living organism. Forensic science uses toxicology to determine if the victim was poisoned, was under the influence of drugs and possibly the cause of death. Throughout history poisoning has been a common method of murder. This is partly because many substances can be poisonous and partly because poisoning leads doctors to believe that there is a medical explanation. Poisons detected through toxicology can range from carbon monoxide to standard medication mixtures. Accidental deaths can also be caused by medicine such as Atropine or Thallium. Atropine is a poisonous substance found in some plant but when used medically, it is used as a muscle relaxant. Thallium is a chemical element with very poisonous compounds. However, toxicology does not only cover poisons, it can also be helpful in finding foreign substances in the body that may be harmful such as, alcohol, illegal drugs, or industrial chemicals. This piece is connected to the case because evidence shows that Aaron Lee had been drinking the night of the accident. There could also be evidence from this test whether he was using or forced to use drugs. The first person to discover the idea of a chemical process for discovering poison was Dr. Hermann Boerhaave. His testing method was very simple; testing the different smells of poisons. Since then, toxicology has been a more complicated and much more accurate process.
Toxicology is a known as a control sample. This means a sample that was collected and is analyzed to further research the crime. This is because it is evidence collected biologically. It has been tested through blood, hair, saliva or other bodily products. Toxicology in forensics can be used in many ways such as proving a DUI or furthering research on a murder. Although poisoning isn’t the most common way of killing people anymore, there is still a combined average of 3,070,000 people dying each year from drugs and alcohol. Blood samples are the most common way to collect toxicology reports. Urine is used frequently as well, for it’s ability to hold drug substances longer than blood. This makes it more clear what the substances being used were and how much of it there was. Toxicologists must also perform post-mortem exams and collect samples to test them. These exams can also be achieved at the request of someone. Any of these steps can lead to decisions on whether it was forced or self-implicated; enough to kill them or not.
One main process of toxicology is called gas-liquid chromatography. Chromatography is a laboratory process of separating different mixtures. Gas chromatography is done by using a chromatograph machine in order to mechanically separate mixtures and chemicals. The first step in this process is to collect the mixture(s) that need to be tested. Always make sure to have clean and sanitary tools during this process as this can affect results. Insert the syringe into a chamber to test the materials in a gas substance. The liquid samples are then vaporized. The materials with more interaction with the machine then separate from those with less. Gas streams are analyzed every so often and then at the end of the machine’s process the separated materials can be determined and analyzed further.
Chromatography is the main method that forensic scientists use in toxicology and they’re many other methods, however during an autopsy scientists can use different approaches in gathering samples from patients. Whether this be blood, saliva, hair, or urine. Gas-liquid chromatography is the most effective approach to finding evidence from forensic toxicology.
One of the main advancements in forensic toxicology has been the upgrade of laboratory practices. Laboratory practices are extremely important in all kinds of science, not just forensics. This is because having good lab methods is the only way to be sure of the accuracy of your testing. There have also been advancements in the machines used for toxicology. The machines have become more precise and available for more types of testing.
Aaron Lee tested positive for Opioids, Oxycodone, Alcohol, and Ethanol. The alcohol was obvious during this investigation because there were liquor bottles spread over the crime scene. Aaron had very clearly been drinking around the time of the death. His wife had also been prescribed a bottle of oxycodone for reasons unknown and the bottle had his fingerprints on it. These pieces of evidence are all a contribution the solving of this crime and will lead the investigation further.
http://www.crimelibrary.com/criminal_mind/forensics/toxicology/2.html
http://abft.org/files/WHAT%20IS%20FORENSIC%20TOXICOLOGY.pdf
http://emedicine.medscape.com/article/1680257-overview
http://en.wikipedia.org/wiki/Forensic_toxicology#Gas_chromatography
http://www.chemguide.co.uk/analysis/chromatography/gas.html
http://en.wikipedia.org/wiki/Gas_chromatography#Methods
http://www.chemguide.co.uk/analysis/chromatography/gas.html
http://hiq.linde-gas.com/en/analytical_methods/gas_chromatography/index.html
Nuclear DNA
Nuclear DNA is DNA contained within the nucleus of eukaryotic organism. DNA testing only became popular in the late 20th century. This is because of the lack of technology prior to this time. Forensic departments use nuclear DNA in many cases and manage to find an abundance of answers. DNA is extremely helpful in forensic science because it can directly link a person to a crime. This can also be true with fingerprints, however the chances of accuracy in DNA testing are much higher.
DNA is a specific picture that belongs to a specific person. Therefore, its uses in forensics are very helpful> Nuclear DNA is an even more specific type of DNA. This type of DNA stores a person’s entire genetic blueprint on chromosomes. There is also mitochondrial DNA. The difference between the two is that in a single cell, only one copy of nuclear DNA may be found, but up to 10,000 mitochondrial copies may be discovered. Also, nuclear DNA is inherited from both parents instead of solely the mother. DNA sequences are also longer in males than in females and therefore DNA is also used to discover the sex of an individual. Post mortem individuals’ DNA will also break down due to the absence of living cells.
Finding any type of DNA is done through a similar process. Replicating is done through a process of PCR (Polymerase Chain Reaction). Polymerase is helpful because during this process, only a small amount of original DNA is needed to replicate billions of times. The first step of PCR is to collect your sample DNA. This is any DNA found at the crime scene. The next thing to do is purify the DNA cells. The first step of this is to create a lysis buffer and add your DNA to it. Lysis means ‘to separate’. Lysis buffer separates the cell membrane to get to the DNA. Put the test tube of the DNA in warm water and wait. Next, add salt water to your lysis buffer solution. This causes other debris to stick together. Next place the sample tube in the centrifuge. This machine spins the tube fast and debris falls to the bottom and DNA strands float. Now separate the different materials. Add isopropyl alcohol to the tube. Repeat placing the DNA in the centrifuge and separate. This causes the DNA to dry for further analysis. PCR is a series of steps based upon heating and cooling the DNA solution to create copies. First, move the extracted DNA into the PCR tube. Next add primers to the solution to attach onto the DNA. Now add nucleotides (a compound related to phosphates). Last, add the DNA Polymerase which are like little machines that can read the DNA. The first temperature is 95 degrees Celsius, which causes the double helix to separate into 2 single strands of DNA. Next, drop the temperature to 50 degrees Celsius, and this will cause the primers to attach to the strands. Last, go to 72 degrees Celsius, which causes the polymerase to attach as well. After several of these processes the correct DNA will start to show. Collect this and move on to gel electrophoresis. Gel electrophoresis is a method of separating DNA. The gel is the image creator of this process. It shows you the different lengths of the DNA and enables you to find the DNA fingerprint, which is a piece of your DNA that makes you unique. This is important in forensics because of the direct link from DNA to person. DNA is a type of associative evidence.
The main methods of finding nuclear DNA are using a lysis buffer to separate the cell membrane from the wanted DNA, using PCR to separate the different elements of the DNA, and finally using gel electrophoresis to identify the DNA fingerprint. Working in any way with DNA is a complicated process and therefore, the range of methods is simple and general.
Advancements in DNA research are always coming about. Though, many methods remain the same. Technology has improved greatly causing the findings of DNA in forensic sciences to become more accurate.
During the crime scene investigation completed in class, we used the DNA of 2 different people. Scott Henderson and Aaron Lee. We extracted Aaron’s blood when he was found dead at the scene of the crime. When further investigating, we discovered that Aaron and Scott have the same blood type. We further found some of Aaron’s blood on Scott’s sink. Therefore, Scott Henderson killed Aaron Lee.
http://en.wikipedia.org/wiki/Polymerase_chain_reaction#Procedure
http://www.fbi.gov/about-us/lab/biometric-analysis/dna-nuclear
http://www.sfu.museum/forensics/eng/pg_media-media_pg/adn-dna/
http://en.wikipedia.org/wiki/Nuclear_DNA
http://learn.genetics.utah.edu/content/labs/extraction/
http://learn.genetics.utah.edu/content/labs/pcr/
http://learn.genetics.utah.edu/content/labs/gel/
DNA is a specific picture that belongs to a specific person. Therefore, its uses in forensics are very helpful> Nuclear DNA is an even more specific type of DNA. This type of DNA stores a person’s entire genetic blueprint on chromosomes. There is also mitochondrial DNA. The difference between the two is that in a single cell, only one copy of nuclear DNA may be found, but up to 10,000 mitochondrial copies may be discovered. Also, nuclear DNA is inherited from both parents instead of solely the mother. DNA sequences are also longer in males than in females and therefore DNA is also used to discover the sex of an individual. Post mortem individuals’ DNA will also break down due to the absence of living cells.
Finding any type of DNA is done through a similar process. Replicating is done through a process of PCR (Polymerase Chain Reaction). Polymerase is helpful because during this process, only a small amount of original DNA is needed to replicate billions of times. The first step of PCR is to collect your sample DNA. This is any DNA found at the crime scene. The next thing to do is purify the DNA cells. The first step of this is to create a lysis buffer and add your DNA to it. Lysis means ‘to separate’. Lysis buffer separates the cell membrane to get to the DNA. Put the test tube of the DNA in warm water and wait. Next, add salt water to your lysis buffer solution. This causes other debris to stick together. Next place the sample tube in the centrifuge. This machine spins the tube fast and debris falls to the bottom and DNA strands float. Now separate the different materials. Add isopropyl alcohol to the tube. Repeat placing the DNA in the centrifuge and separate. This causes the DNA to dry for further analysis. PCR is a series of steps based upon heating and cooling the DNA solution to create copies. First, move the extracted DNA into the PCR tube. Next add primers to the solution to attach onto the DNA. Now add nucleotides (a compound related to phosphates). Last, add the DNA Polymerase which are like little machines that can read the DNA. The first temperature is 95 degrees Celsius, which causes the double helix to separate into 2 single strands of DNA. Next, drop the temperature to 50 degrees Celsius, and this will cause the primers to attach to the strands. Last, go to 72 degrees Celsius, which causes the polymerase to attach as well. After several of these processes the correct DNA will start to show. Collect this and move on to gel electrophoresis. Gel electrophoresis is a method of separating DNA. The gel is the image creator of this process. It shows you the different lengths of the DNA and enables you to find the DNA fingerprint, which is a piece of your DNA that makes you unique. This is important in forensics because of the direct link from DNA to person. DNA is a type of associative evidence.
The main methods of finding nuclear DNA are using a lysis buffer to separate the cell membrane from the wanted DNA, using PCR to separate the different elements of the DNA, and finally using gel electrophoresis to identify the DNA fingerprint. Working in any way with DNA is a complicated process and therefore, the range of methods is simple and general.
Advancements in DNA research are always coming about. Though, many methods remain the same. Technology has improved greatly causing the findings of DNA in forensic sciences to become more accurate.
During the crime scene investigation completed in class, we used the DNA of 2 different people. Scott Henderson and Aaron Lee. We extracted Aaron’s blood when he was found dead at the scene of the crime. When further investigating, we discovered that Aaron and Scott have the same blood type. We further found some of Aaron’s blood on Scott’s sink. Therefore, Scott Henderson killed Aaron Lee.
http://en.wikipedia.org/wiki/Polymerase_chain_reaction#Procedure
http://www.fbi.gov/about-us/lab/biometric-analysis/dna-nuclear
http://www.sfu.museum/forensics/eng/pg_media-media_pg/adn-dna/
http://en.wikipedia.org/wiki/Nuclear_DNA
http://learn.genetics.utah.edu/content/labs/extraction/
http://learn.genetics.utah.edu/content/labs/pcr/
http://learn.genetics.utah.edu/content/labs/gel/