Forensic Science Essay

Answer one of the below questions that has not been answered by anyone else, and then respond to submissions from at least two classmates

Option 1: List and describe the general features of bloodstain formation.

Option 2.  A criminalist studying a dyed sample hair notices that the dyed color ends about 1.5 centimeters from the tip of the hair.  Approximately how many weeks before the examination was the hair dyed?  Explain your answer.

Option 3.  Following are descriptions of several hairs.  Based on these descriptions, indicate the likely race of the person from whom the hair originated.

             a.  Evenly distributed, fine pigmentation.

             b.  Continuous medullation.

             c.  Dense, uneven pigmentation.

             d.  Wavy with a round cross-section.

Option 4.  Criminalist Pete Evett is collecting fiber evidence from a murder scene.  He notices fibers on the victim’s shirt and trousers, so he places both of these items of clothing in a plastic bag.  He also sees fibers on a sheet near the victim, so he balls up the sheet and places it in as separate plastic bag.  Noticing fibers adhering to the windowsill from which the attacker gained entrance, Pete carefully removes it with his fingers and places it in a regular envelope.  What mistakes, if any, did Pete make while collecting this evidence?

Option 5.  You are investigating a hit-and-run accident and have identified a suspect vehicle.  Describe how you would collect paint to determine whether the suspect vehicle was involved in the accident.  Be sure to indicate the tools you would use and the steps you would take to prevent cross-contamination.

Option 6.  While investigating a murder scene, police gather evidence that includes a dead body riddled with stab sounds, fingerprints on a bloody knife found near the body, and a ticket stub from a theater several miles away from the scene.  Detectives determine that the knife belongs to the victim, but matched prints on the knife to an acquaintance of the victim.  When questioned, the acquaintance claims he was at the movies at the time of the murder – the same movie shown on the ticket stub at the scene.  What direct physical evidence connects the acquaintance to the crime scene?  What circumstantial evidence connects him to the scene?  What can you conclude about the acquaintance’s involvement solely from direct physical evidence and deductive reasoning?  What might you conclude considering circumstantial evidence and inductive reasoning as well? 

Option 7: Criminalist Mick is collecting evidence from a fire scene.  He gathers about a quart of ash and soot debris from several rooms surrounding the point of origin.  He stores the debris in a new, clean paint can, filled about three-quarters full.  Seeing several pieces of timber he believes may contain accelerant residues, he cuts them and places them in airtight plastic bags.  A short time later a suspect is arrested and Mick searches him for any signs of an igniter or accelerant.  He finds a cigarette lighter on the suspect and seizes it for evidence before turning the suspect over to the police.  What mistakes, if any, did Mick make in collecting the evidence?

Option 8: List and describe the four types of impact bloodstain spatter patterns.

Option 9: What are the characteristics of gunshot spatter and of cast-off spatter?

Option 10: Describe the procedures to document bloodstain pattern evidence.

Option 11: List and give the characteristics of seven of the major generic fibers not addressed by another student.

Option 12: The identification and comparison of manufactured fibers consists of at least three examinations and comparisons.  List and describe them.

Option 13: Briefly describe the chemistry of fire.

Option 14: Define conduction, radiation, and convection.

Option 15: List the characteristics of a fire scene that would indicate the use of accelerants.