Forensic Science Overview - Chapters 1, 3, 24

The 2009 NAS report highlighted serious concerns about the scientific validity and reliability of many forensic disciplines, particularly those lacking a strong scientific foundation. It called for greater scientific rigor, standardization, and validation of forensic methods. The report advocated for increased research and funding for forensic science, emphasizing the need for more robust scientific evidence in criminal justice.

Physical evidence is tangible, material objects found at a crime scene, such as fingerprints, weapons, or DNA. Non-physical evidence is intangible, consisting of verbal statements, written documents, or electronic data. Examples include eyewitness testimony, audio recordings, or digital footprints.

Chain of custody refers to the chronological documentation of the handling, storage, and transfer of evidence from the crime scene to the court. Maintaining a complete and accurate chain of custody ensures the evidence's integrity and prevents tampering or contamination, contributing to the admissibility of the evidence in court.

<p>Individual characteristics are unique traits found on evidence that can be linked to a specific source, like fingerprints, DNA profiles, or unique markings on a weapon. Class characteristics are common features found in a group of similar objects but not unique to a single source, such as the type of blood or fiber.</p> Signup and view all the answers

<p>Probable cause is a legal standard requiring reasonable belief that a crime has been committed and that evidence related to that crime is likely to be found in a particular location. Probable cause is needed for obtaining a warrant to search a location or to arrest a suspect. It ensures that searches and seizures are reasonable and not arbitrary, respecting individual rights.</p> Signup and view all the answers

<p>The Frye standard, known as the &quot;general acceptance test,&quot; requires that scientific evidence be generally accepted in the relevant scientific community for it to be admissible in court. The Daubert standard, on the other hand, focuses on the reliability of the scientific evidence, requiring it to be based on sound scientific methodology and data, even if not widely accepted. Daubert allows for a greater degree of flexibility and scientific scrutiny compared to Frye.</p> Signup and view all the answers

<p>Relevance refers to the logical connection between the evidence and a fact in issue. Materiality, on the other hand, focuses on whether the evidence has a bearing on the outcome of the case. While relevance addresses the logical connection, materiality centers on the legal significance of that connection. Both concepts are essential for determining the admissibility of evidence.</p> Signup and view all the answers

<p>The gatekeeper in a trial is responsible for overseeing the admissibility of evidence presented by both the prosecution and the defense. Typically, the judge acts as the gatekeeper and ensures that only relevant, reliable, and admissible evidence is presented to the jury. This ensures that the trial is fair and conducted according to the rules of evidence.</p> Signup and view all the answers

<p>An expert witness possesses specialized knowledge and training in a particular field, enabling them to provide opinions and interpretations based on their expertise. A lay witness, on the other hand, is a non-expert who can only testify to facts they have personally witnessed. Expert testimonies are distinguished by their ability to provide specialized opinions and interpretations, while lay witness testimonies are limited to factual observations.</p> Signup and view all the answers

<p>Paul Kirk, known for his work in trace evidence analysis and pioneering the use of microscopy in forensic science, revolutionized the field's approach to identifying and analyzing physical evidence. Sir Alec Jeffries developed DNA fingerprinting, a groundbreaking technique that revolutionized forensic identification. Kary Mullis invented PCR, a technique for replicating DNA, making it possible to analyze minute amounts of DNA and revolutionizing forensic DNA analysis. Edmond Locard, known for his &quot;Locard's Exchange Principle,&quot; asserted that every contact leaves a trace, laying the foundation for the study of trace evidence in forensic science.</p> Signup and view all the answers

The application of scientific methods to investigate crimes.

The process of maintaining and documenting evidence handling.

Physical, non-physical, real, demonstrative, known, and unknown evidence classifications.

Evidence that can be linked to a specific source.

A report that evaluated the state of forensic science, raising concerns about reliability.

A reasonable belief that a crime has been committed, needed for searches and arrests.

A person with specialized knowledge called to testify in a trial.

A standard to determine the admissibility of scientific evidence based on general acceptance.

Procedures to ensure quality standards in forensic analysis.

Testimony based on what others said, not direct knowledge.