Crime Scene Evidence Paper- CRJ311

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Crime Scene Evidence Analysis Report xxxxxxx The University of Arizona Global Campus CRJ 311: Forensics Professor Dr. Clearfield November 26, 2023

Crime scene evidence is important in a criminal case because it provides the foundation for an investigation and helps find the perpetrator responsible for a crime. I have been appointed by the Crime Scene Response Unit (CSRU) manager to be the lead investigator on a double homicide that has happened in Metro City. A white 2016, Chevrolet Impala was reported abandoned about 10 miles north of Metro city and smears of blood were found on the dashboard, steering wheel, and both front seats. A duffle bag was found with blood smears along with stock certificates and a diamond earring. The certificates contained an address that led police officers to the scene. When they arrived, they found the door locked, with no forced entry however upon entering officers discovered a male and female who were deceased. The living room looked ransacked and an open safe was located, they also found pictures of the victims' 15-year-old daughter whose location is unknown, and her phone was found in one of the bedrooms. In this paper I will discuss how to protect the crime scene, how to identify and document evidence, evidence handling, testing, and standards for the admissibility of evidence; scientific testing, expert testimony at trial and how forensic science contributes to a more just society. When law enforcement officials respond to a crime scene, it is important for them to secure the area. By doing this they can put tape to block off the location of where the crime has occurred and to minimize from people entering the space so there is no contamination of evidence and wait for the response team to arrive to enter the premises and collect evidence. Upon arriving at the scene, an initial survey must be conducted to determine what evidence is around the crime scene and to determine how much search and evidence should be collected (Gaensslen & Larsen, 2019). Near the front door, a helmet and skateboard were left behind, nothing else is around only a broken window that officials broke to get into the house. Next, we must start our search inside the house, and it would be a good idea to wear gloves before entering

to examine items and for them not to get contaminated. To protect the scene from contamination or loss of evidence we must document the scene and evidence. This can include “looking at patterns such as blood spatter, overturned furniture, out-of-place objects, and it could include individual items that will be collected later” (Gaensslen & Larsen, 2019, Section 2.3, “Steps in Crime Scene Processing,” para. 4). We can take notes of what is found, sketches, take photos and video of items found. Lastly, we must identify, collect, and preserve the evidence found in the correct manner “collecting and preserving evidence consist of using proper collection methods, using proper containers, and properly storing evidence in the lab or property storage” (Gaensslen & Larsen, 2019, Section 2.3, “Steps in Crime Scene Processing,” para. 25). This is important because having good crime scene management skills ensures that everything is properly collected so it can be admissible during court. The first piece of evidence found in the crime scene was a deceased male on the floor who had 3 gunshots on his abdomen. Blood spatter was around the floor and there were bloody footprints as well. To collect this evidence, we must take photos, take notes of how the body was found, the location of where the items were found, and video can be taken as well. When collecting the blood, it must first be dried out and then packed in paper. If it is stored differently there is a risk of bacteria getting in it which can destroy the evidence, as for liquids they should be collected and stored in appropriate containers such as glass or plastic and labeled (“Crime scene and DNA..,” n.d). The T-shirt with wounds can also be taken to the lab for further examination and be placed in a clear plastic bag. In one of the bedrooms a deceased female was found whose throat had been slashed, blood spatter was under her, and a bloody knife was beside her. An open safe and an open jewelry box were found when entering the room. The bloody knife can be placed in a container that is strong to prevent it from ripping through and the phone

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that was found on the bed should be placed in a nonconducting container to prevent electrical damage (Gaensslen & Larsen, 2019). The jewelry box can be placed in a bag, but we can also check for fingerprints on the knife, jewelry box and safe. Forensic investigators can dust surfaces with a dark powder that sticks to the prints to then reveal them, then they can use tape to lift the fingerprint. "The stain is transferred to the adhesive side of the tape, which may then be secured on a clear piece of acetate for submission to the laboratory" ("Crime scene and DNA..", n.d, p.7). In the garage, the white Chevrolet Impala was left there for examination, and it looks like there were some tire impressions on the floor. This could help us further with our investigation by photographing that evidence. The blood spatter on the dash, steering wheel and two front seats can also be collected and photographed. Everything must be collected in a different way because the process of collecting evidence is very delicate and any mistake can damage the evidence. Chain of Custody is a major step while documenting evidence. It is used to document and maintain the chronological history of the evidence. It starts from the very beginning when an officer responds to a crime scene and all the documenting provides a paper trail of who handled what and how it was handled (“Chain of custody,” n.d). Everything must be recorded, photographed, noted, and labeled appropriately to determine that the evidence is the one that was initially collected from the crime scene. “An item of evidence might go from the scene, to the department property room, to the lab receiving unit, to the lab master storage vault, to an examiner's bench, back to the lab master storage vault, back to the department property room, and finally to the court's evidence storage room and to the courtroom” (Gaensslen & Larsen, 2019, Section 2.3, “Steps in Crime Scene Processing,” para. 38). This allows for the evidence to be admissible in court and without it the court can deem the evidence not reliable. Failure to follow the chain of custody means that “t he evidence may be inadmissible in the court leading to

serious questions regarding its legitimacy, integrity, and the examination rendered upon it” ( “Chain of custody,” n.d, p.1). This means that a defendant cannot be convicted in court if the evidence collected is not properly handled. Some of the evidence found at the crime scene may be subjected to preliminary field or laboratory testing. Evidence that may be tested at the scene is the blood spatter, the bloody footprints, the tire impressions, and any bodily fluids. For example, the bloody footprints and tire impressions cannot be lifted without the evidence getting damaged, so they have to be analyzed at the scene by taking video or photographs. To test the blood spatter at the scene it can be photographed “a scale or ruler is placed next to the bloodstain to provide accurate measurement and photos are taken from every angle. Video and sketches of the scene and the blood stains is often used to provide perspective and further documentation” (“Bloodstain Pattern Analysis,” n.d., p. 1). The bloodstain pattern can help determine what happened and can indicate the velocity something happened for example, a gunshot wound will typically form small droplets and go all around the area (“Bloodstain Pattern Analysis,” n.d). Bodily fluids are not always visible to the naked eye and a UV light must be flashed around to see what the fluid could be. Evidence that can be taken to the lab for testing is the DNA evidence found such as fingerprints left behind from the suspect, the gunshot residue left behind from the male’s gunshot wounds, and trace evidence such as the victim’s hair, fibers, and any broken glass. Gun shot residue can be identified by its composition and particle structure and can be further analyzed at a lab with a special kit that contains metal studs with sticky tape for the residue to adhere to (Gaensslen & Larsen, 2019). Further analysis is done by using microscopes that help identify the residue “These microscopes are very powerful, enabling the analyst to see the particles of gunshot residue. With an attachment called an energy-dispersive X-ray spectrometer, the elemental

composition of the particles can be determined” (Gaensslen & Larsen, 2019, Section 9.4, “Gunshot Residue,” para. 3). Another form of laboratory testing is fingerprints. Once fingerprints are collected at the crime scene, they must be taken to a lab for further testing to be conducted. An examiner looks at the prints, examines the ridges, and identifies if it is a whole print that can be used for further examination if so, the next process is the analysis, comparison, evaluation, and verification (ACE-V) and the pattern of the fingerprint is further examined (Gaensslen & Larsen, 2019). The process allows examiners to carefully look at the print and determine if it is a match to a suspect accused of a crime. In this case, it was also known by officials that the victims would argue with their daughter over her boyfriend who never got a haircut, and who was arrested before which means his fingerprints are on file. He can be the main suspect in this case and the fingerprints left behind may match his. Trace evidence can be collected at the crime scene and analyzed further to determine who is a suspect and what kind of object was used, for example a murder. In this case, hair can be taken from the victim and analyzed at the lab under a microscope to compare the hairs found to see if they can potentially be from the daughter’s boyfriend. Knowing where the hair came from or if it belongs to an animal or human can help narrow down the suspect because no one realizes that the piece of evidence that can hardly be seen is the one that connects to the suspect. The male victim’s shirt can also be taken to the lab to have a forensic scientist analyze the holes and help determine what type of gun was used since there was no gun left at the scene. Some of the findings of the preliminary field testing and laboratory testing can yield different results if not tested properly. Laboratory testing is for testing that needs further analyzation and for details to be looked at closely and many of these labs are back logged due to the high number of requests needed from law enforcement or courts. Obtaining faster results

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means using field testing as an alternative however “w hen forensic testing is removed from the lab and placed in the field, it opens up many possibilities for evidence to be destroyed or contaminated and for results to be used in ways that exceed their appropriate scope” (Stout, n.d., p.1). This makes it difficult for the evidence to be admissible in court. We know that preliminary field testing and laboratory testing is used to help a crime scene investigation and even though these tests are conducted it is not enough to bring these results to trial; a forensic scientist must follow the scientific standards for them to be admissible in court. In this crime scene, we located and collected evidence such as DNA, fingerprints, and trace evidence to help us solve this crime. We need to analyze the current standards for the admissibility of scientific evidence found at the scene. DNA evidence is considered the most reliable form of evidence to present in court and the most common way to analyze DNA is through the polymerase chain reaction (PCR) analysis. First the DNA must be separated from the tissue or material it is found from. Then the technician needs to determine how much DNA there is available for further testing then the DNA segment gets multiplied into many cycles to reproduce copies of it which is the PCR analysis (Gaensslen & Larsen, 2019). The current standard for DNA to be admissible in court is that an expert’s testimony must be able to interpret the DNA results with a scientific theory applied for it to be valid. Daubert v. Merrell Dow Pharmaceuticals, Inc., was a case that established the standard for admissible evidence such as DNA to be admissible in court with expert testimony with scientific reasoning. For the fingerprints that were collected the standard is similar to DNA analysis and in court the evidence is admissible by expert testimony and the results obtained must be interpreted for the jury to understand. The acceptance of this evidence is from the Daubert v. Merrell Dow Pharmaceuticals, Inc., case and has been applied to fingerprint evidence presented in court.

Trace evidence includes hair fibers, glass, paint, soil, etc. The trace evidence found at the crime scene can be presented in court by the identification of the sources found for example if there was a burglary and there is a broken bottle, fingerprint traces are bound to be left behind and the pieces of glass can also be examined to see if it relates to the broken bottle and or hair may be left behind at the scene which can help identify a suspect. In trial expert testimony is important and the prosecution will try to convince the jury that trace evidence such as hair fibers or glass were found at the crime scene that match the suspect while the defense could say that trace evidence is everywhere, and glass particles are common at a crime scene (Gaensslen & Larsen, 2019). The delivery of the results must be backed up with tests from a laboratory for the information to be admissible in a court room. Although there are certain standards to follow for the admissibility of evidence in court there also may be some possible challenges of admissibility. For example, there are challenges of DNA evidence being admissible in court because in many criminal cases prosecutors are asking for DNA testing to be conducted and with so many cases and requests everything cannot be completed on time or even accurately. Some issues of these high demands can lead to improper laboratory protocols, overworked technicians which can then do poor testing on evidence (Shelton, 2012). Other issues is that DNA can easily be contaminated which can provide inaccurate results and breaking the chain of custody is another reason DNA sometimes cannot be used in court. In the case of Frye v. United states, the court held that the procedure of how the DNA was tested in this case did not comply with the standards of reliability due to the expert's testimony. For fingerprints, every person has their own unique fingerprint, for example, identical twins will never have the same fingerprints and therefore can be identified. This method has helped solve crimes and convict someone in court however admissibility issues do exist as well

because fingerprints are not always reliable. The way that latent print examiners analyze a print is "is too broad to ensure repeatability and transparency; and does not guarantee that two analysts following it will obtain the same results" (Cooper, n.d, p.8). There can be errors when identifying a print and matching it to a specific person. In order to avoid these issues in court the chain of custody must be followed, and the testing should be conducted with the appropriate protocols to ensure its reliability in court. Experts must have knowledge of the scientific evidence standards and must be proven with laboratory tests. Following a valid methodology and properly using forensic science at trial contributes to sustaining a more just society. New technology has contributed to this because this means more advancement in the criminal justice system and for more accurate convictions to take place. “Scientists and technicians are being armed with increasingly sophisticated technologies that they can use to help bring criminals to justice and prevent the innocent from going to prison” (“National Institiute of Justice,” n.d. (p. 5). Forensic scientists must follow all protocols of an analysis of evidence because “the credibility of the evidence often depends upon the integrity of the handlers, examiners, experts, and presenters of that evidence” (“Forensic science,” 2017, p.1). The current methods of testing are designed to create accurate results and they take time to conduct, and the results should be interpreted by an expert that understands the standards of scientific evidence. Protecting a crime scene, documenting, handling, and testing, evidence is how forensic science creates a foundation for a crime scene. Standards for the admissibility of evidence; scientific testing, and expert testimony at trial is what allows forensic science to thrive in the criminal justice system, convict criminals, and exonerate innocent people. Forensic science has not only helped the criminal justice system, but it has created a more just society. With new

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scientific innovations the criminal justice system will continue to improve and create a better generation.

References Bloodstain pattern analysis . Bloodstain Pattern Analysis: How It’s Done. (n.d.). https://www.forensicsciencesimplified.org/blood/how.html Cooper, S. L. (n.d.). Challenges to fingerprint identification evidence ... - Mitchell Hamline. https://open.mitchellhamline.edu/cgi/viewcontent.cgi?article=1027&context=mhlr Crime scene and DNA basics for forensic analysts: Collection techniques . National Institute of Justice. (n.d.). https://nij.ojp.gov/nij-hosted-online-training-courses/crime-scene-and-dna- basics-forensic-analysts/evidence-crime-scene/collection-techniques Chain of custody - statpearls - NCBI bookshelf. (n.d.). https://www.ncbi.nlm.nih.gov/books/NBK551677/ Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993) . Justia Law. (n.d.-b). https://supreme.justia.com/cases/federal/us/509/579/ Forensic science . Office of Legal Policy U.S. Department of Justice. (2023, May 17). https://www.justice.gov/olp/forensic-science#:~:text=Forensic%20scientists%20examine %20and%20analyze,an%20innocent%20person%20from%20suspicion . Frye v. United States, 293 F. 1013 (D.C. Cir. 1923) . Legal research tools from Casetext. (1923, December 3). https://casetext.com/case/frye-v-united-states-7 Gaensslen, R. E., & Larsen, K. (2019). Introductory forensic science (2nd ed.) . Retrieved from https://content.uagc.edu/

Stout, P. (n.d.). Caution is necessary when expanding field testing capabilities . National Institute of Justice. https://nij.ojp.gov/topics/articles/caution-necessary-when-expanding-field- testing-capabilities Shelton, D. E. (2012). Forensic science evidence: Can the law keep up with science? Retrieved from http://ebookcentral.proquest.com National Institute of Justice. (n.d.-a). The impact of Forensic Science Research and Development. https://www.ojp.gov/pdffiles1/nij/248572.pdf

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