You Are A Crime Scene Investigator On A Homicide And You Fin

You Are A Crime Scene Investigator On A Homicide And You Find That Yo

You are a crime scene investigator on a homicide, and you find that you have several types of evidence that must be photographed, logged, and recovered from that scene. More specifically, there is drying blood on the floor that needs to be collected, a handgun and several shell casings near the victim, and several hairs that are still in the hand of your deceased victim. For this assignment, you are to do the following: Explain how you would recover dried blood, a handgun, shell casings, and hairs that are at the crime scene. What tools you would use to recover the evidence? How would you package the evidence for safekeeping and transportation? What types of tests could be performed on this evidence at the crime lab? Provide APA citation and references for your material.

Paper For Above instruction

As a crime scene investigator tasked with securing evidence from a homicide scene, meticulous procedures are essential to preserve the integrity of evidence for forensic analysis. The recovery of dried blood, a firearm with shell casings, and hairs requires specific tools and protocols designed to prevent contamination and degradation, ensuring reliable results in subsequent laboratory testing.

Recovery of Dried Blood

The collection of dried blood stains involves utilizing clean, disposable tools such as sterile scalpels or disposable spatulas to carefully lift blood residues from the surface. Since blood is biological evidence, employing sterile forceps and swabs with appropriate preservative mediums can be advantageous. The scene must be photographed before collection, maintaining a detailed log to document the evidence’s original position and condition. Dried blood can then be transferred into properly labeled, airtight containers such as paper envelopes or cardboard boxes to avoid mold growth and degradation, as plastic containers may promote moisture retention and deterioration. Proper packaging prevents contamination and allows for accurate forensic testing like DNA analysis or presumptive blood tests (Saferstein, 2018).

Recovery of Firearms and Shell Casings

The handgun, located near the victim, should be carefully removed using powder-free, nitrile-coated gloves to prevent contamination of fingerprints or DNA. The firearm is secured in a cardboard or plastic firearm evidence box, with the serial number recorded for chain-of-custody documentation. Shell casings found nearby should be collected with clean, metal forceps and placed into a semi-rigid, tamper-evident container such as an evidence box designed for firearms or ammunition. The scene photography should include close-up shots before removal. Proper labeling, including the location, date, and case number, ensures chain-of-custody integrity. Packaging precautions are crucial to prevent damage to fingerprints or ballistic markings (Harris & Bevel, 2018).

Recovery of Hairs in the Victim’s Hand

Hairs found in the victim’s hand are recovered using clean forceps and stored individually in paper envelopes to prevent moisture buildup, which can compromise DNA integrity. It is important to avoid excessive handling or overlapping hairs, as this could contaminate the samples. The hairs should be labeled with details regarding their origin, and scene photographs should document their position. Preserving these hairs is essential for DNA comparison, which can help identify potential suspects or victims (Pollanen & Rieder, 2019).

Packaging and Transportation of Evidence

All recovered evidence must be carefully labeled with case numbers, dates, times, and collector initials. Biological evidence, such as blood and hairs, should be stored in paper containers to prevent mold and degradation, while firearms and shell casings are kept in rigid, tamper-evident containers. Chain of custody documentation is critical throughout the process. Evidence should be transported in a secure, organized manner, minimizing exposure to environmental factors that could compromise analysis (Saferstein, 2018).

Forensic Testing of Evidence

The dried blood can undergo presumptive tests such as the Kastle-Meyer test to quickly indicate the presence of blood, followed by confirmatory tests like the Takayama or Teichmann tests. DNA analysis can be performed to identify the individual from whom the blood originated. The firearm and shell casings can be examined using ballistic analysis, including firearm identification and comparison microscopy to match shell casings to the recovered firearm. Hairs can be subjected to microscopic analysis for origin evaluation, and DNA testing can establish whether the hairs belong to the victim or potential suspects. These tests help establish the sequence of events and link evidence to suspects or the scene itself (Harris & Bevel, 2018; Houck & Siegel, 2015).

Conclusion

In sum, the careful collection, packaging, and testing of biological and physical evidence are fundamental steps in forensic investigations. Precise techniques and proper evidence handling protocols ensure that evidence remains uncontaminated, reliable, and admissible in court, ultimately contributing to solving the homicide case effectively.

References

• Harris, J. R., & Bevel, T. (2018). Forensic ballistics: Theory and practice. CRC Press.
• Houck, M. M., & Siegel, J. A. (2015). Fundamentals of forensic science (3rd ed.). Academic Press.
• Pollanen, M. S., & Rieder, A. (2019). Forensic pathology. CRC Press.
• Saferstein, R. (2018). Criminalistics: An introduction to forensic science (12th ed.). Pearson.