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Examination and Processing of the Crime Scene

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SCENE

Joe stopped for a beer at the Turn-a-Round Lounge in Smalltown on his way home from work. He ran into his ex-girlfriend, Michelle, and her new boyfriend, Sam. Joe and Sam got involved in a heated confrontation, and bottles and fists started to fly. Sam pulled out a knife and stabbed Joe in the chest, nicking his aorta. Despite the bartender's attempts at CPR and putting pressure on the wound, Joe bled to death before the EMTs arrived.

When the fight began, there were 20 or so patrons in the lounge. When EMTs and police arrived on the scene, only two of the patrons and the bartender remained. Michelle and Sam were gone. The EMTs attempted CPR, but Joe was already dead. Two patrol officers secured the scene and detained the three remaining witnesses.

Upon examining the scene, police find three bloody footprints by the door where Michelle and Sam exited and tire tracks in the dirt parking lot where they made a hasty exit. Police obtain latent prints on a number of different surfaces using alternative light sources.

Police execute a search warrant at Michelle's residence and Joe's apartment. They find several threatening letters at Michelle's home that she claims were written by Joe.

ASSIGNMENT

Sam cut his finger when he stabbed Joe. Some of the blood from Sam's cut mixed with the blood on Joe's shirt. The Smalltown prosecutor has asked you to prepare a 3-5 page briefing for her that explains whether the lab can isolate Sam's DNA from Joe's and, if so, how that would be done. The prosecutor wants to prove that it is Sam's blood beyond an absolute certainty. Please explain whether or not this is possible and explain your reasoning. She has asked you to describe how the lab would process the evidence and what tests would be used. She specifically asked whether nuclear or mitochondrial DNA tests would be used and asked you to explain the difference. Reference all sources using APA style.

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RESPONSE:

1. I need help getting started. Any help will be appreciated. Thank you.

ASSIGNMENT: Sam cut his finger when he stabbed Joe. Some of the blood from Sam's cut mixed with the blood on Joe's shirt. The Smalltown prosecutor has asked you to prepare a 3-5 page briefing for her that explains whether the lab can isolate Sam's DNA from Joe's and, if so, how that would be done. The prosecutor wants to prove that it is Sam's blood beyond an absolute certainty. Please explain whether or not this is possible and explain your reasoning. She has asked you to describe how the lab would process the evidence and what tests would be used. She specifically asked whether nuclear or mitochondrial DNA tests would be used and asked you to explain the difference. Be sure to reference all sources using APA style.

Interesting scenario! Let's take a closer look.

DNA-based technologies have enormous forensic implications in the fight against crime. The lab can isolate Sam's DNA from Joe's, and the samples of blood evidence samples found at the crime scene will be sent to an independent lab capable of performing Nuclear, Mitochondrial, and Short Tandem Repeats. Depending on the sample, the lab will use the method most likely to be most reliable given the amount and quality of the blood sample evidence. Although the prosecutor wants to prove that it is Sam's blood beyond an absolute certainty, no DNA test has 100% reliable; there is some margin of error. But, it is still considered reliable when a match is found.

Mitochondrial DNA MtDNA is perfect for older, smaller or degraded samples.

1. Mitochondria

? Mitochondria (singular: mitochondrion) are structures within cells that convert the energy from food into a form that cells can use. Each cell contains hundreds to thousands of mitochondria.

? Mitochondrial DNA (mtDNA) is Useful for Identifying Victims of ...

Solution Summary

Based on the case scenario, this solution describes how the lab would process the evidence and what tests would be used e.g. nuclear or mitochondrial DNA tests. References in APA format.

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