Show Menu
Cheatography
  1. Home >
  2. Education >

Intro to Forensic Science Cheat Sheet (DRAFT) by

Intro to Forensic Science notes

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Overview

Defini­tion:
Forensic science is the applic­ation of scientific principles and techniques to the invest­igation of crimes. It involves the collec­tion, preser­vation, and analysis of evidence to assist in legal procee­dings.
Scope:
Forensic science encomp­asses a wide range of discip­lines, including biology, chemistry, physics, psycho­logy, and digital sciences. It is used to solve crimes, identify perpet­rators, and support the justice system.
History and Evolution:
Early Beginn­ings: The use of forensic methods dates back to ancient civili­zat­ions, with early examples like finger­pri­nting in ancient China and forensic medicine in ancient Rome.
 
Modern Develo­pment: The formal­ization of forensic science began in the 19th century with the establ­ishment of forensic pathology, toxico­logy, and the use of finger­print analysis.
 
Techno­logical Advanc­ements: The 20th and 21st centuries have seen signif­icant advanc­ements in forensic techno­logy, including DNA profiling, digital forensics, and advanced imaging techni­ques.

Key Discip­lines in Forensic Science

Forensic Biology:
DNA Analysis: The process of identi­fying indivi­duals based on their unique genetic makeup. Techniques include STR analysis, mitoch­ondrial DNA analysis, and Y-chro­mosome analysis.
 
Serology: The study and analysis of bodily fluids, such as blood, semen, and saliva, to identify their presence and source at a crime scene.
 
Entomo­logy: The study of insects to estimate time of death based on the presence and develo­pment stages of insects on decomp­osing bodies.
Forensic Chemistry:
Toxico­logy: The analysis of bodily fluids and tissues to detect the presence of drugs, alcohol, poisons, and other toxic substa­nces.
 
Drug Analysis: The identi­fic­ation of controlled substances found at crime scenes or in a person’s posses­sion.
 
Explosives and Arson Analysis: The examin­ation of materials to identify accele­rants, residues, and other substances related to explosions and fires.
Forensic Anthro­pology:
Skeletal Analysis: The study of human bones to determine identity, cause of death, and other inform­ation, such as age, sex, ancestry, and trauma.
 
Facial Recons­tru­ction: The process of recreating a person’s face from their skeletal remains to assist in identi­fic­ation.
Forensic Pathology:
Autopsy: The medical examin­ation of a body to determine the cause and manner of death. Key components include external examin­ation, internal examin­ation, and toxicology tests.
 
Time of Death Estima­tion: Methods include rigor mortis, livor mortis, algor mortis, and forensic entomo­logy.
Forensic Odonto­logy:
Dental Identi­fic­ation: The use of dental records to identify human remains, partic­ularly in cases where the body is decomposed or otherwise unreco­gni­zable.
 
Bite Mark Analysis: The comparison of bite marks found on victims with the dental impres­sions of suspects.
Forensic Toxico­logy:
Analysis of Poisons: Identi­fying and quanti­fying toxins in the body, including drugs, alcohol, and chemicals.
 
Postmortem Toxico­logy: Determ­ining the role of substances in a person’s death, often involving the analysis of blood, urine, and tissues.
Forensic Psycho­logy:
Criminal Profiling: The analysis of crime scene evidence to develop a psycho­logical profile of the perpet­rator, including likely behavioral patterns and person­ality traits.
 
Competency Evalua­tions: Assessing a suspect’s mental state to determine their ability to stand trial or their respon­sib­ility for their actions at the time of the crime.
 
Victim­ology: The study of victims to understand the dynamics of a crime, including the relati­onship between victim and perpet­rator.
Forensic Digital Analysis:
Cyber Forensics: The invest­igation of digital devices and networks to uncover evidence related to cyberc­rimes, including hacking, fraud, and digital piracy.
 
Mobile Device Forensics: The extraction and analysis of data from mobile devices such as phones and tablets, including text messages, call logs, and GPS data.
 
Network Forensics: The monitoring and analysis of network traffic to detect and invest­igate cyber attacks.

The Forensic Process

Crime Scene Invest­iga­tion:
Securing the Scene: Ensuring that the crime scene is preserved to prevent contam­ination of evidence. This includes setting up barriers and contro­lling access.
 
Evidence Collec­tion: Systematic collection of physical evidence, such as finger­prints, biological samples, weapons, and digital devices. Proper docume­ntation and chain of custody are crucial.
 
Docume­nta­tion: Photog­rap­hing, sketching, and recording detailed notes about the crime scene, including the position of evidence, the condition of the scene, and any observable details.
Laboratory Analysis:
Evidence Proces­sing: Analysis of collected evidence in forensic labora­tories, including chemical tests, DNA profiling, and digital data extrac­tion.
 
Interp­ret­ation of Results: Forensic scientists analyze the results to draw conclu­sions about the evidence, such as identi­fying substa­nces, matching DNA to a suspect, or recovering deleted files.
Reporting and Testimony:
Forensic Reports: Detailed docume­ntation of the methods, findings, and conclu­sions drawn from the analysis of evidence. These reports are crucial in legal procee­dings.
 
Expert Witness Testimony: Forensic scientists may be called upon to testify in court, explaining the evidence, methods used, and conclu­sions to the judge and jury.
 

Legal and Ethical Consid­era­tions

Chain of Custody:
The process of docume­nting the handling of evidence from the time it is collected until it is presented in court. This ensures that the evidence has not been tampered with and is admissible in court.
Admiss­ibility of Evidence:
Frye Standard: A legal standard used to determine the admiss­ibility of scientific evidence, based on whether the method­ology is generally accepted by the scientific community.
 
Daubert Standard: A more stringent standard that requires scientific evidence to be not only generally accepted but also tested, peer-r­evi­ewed, and with a known error rate.
Ethical Issues:
Bias and Object­ivity: Forensic scientists must remain unbiased and objective, ensuring that their findings are based solely on the evidence and not influenced by external pressures.
 
Bias and Object­ivity: Forensic scientists must remain unbiased and objective, ensuring that their findings are based solely on the evidence and not influenced by external pressures.
 
Reporting of Results: Forensic scientists have an ethical obligation to report findings accura­tely, even if they do not support the case of the party that hired them.

Advances in Forensic Science

DNA Techno­logy:
Next-G­ene­ration Sequencing (NGS): Allows for more compre­hensive and faster analysis of DNA, including degraded samples, and can provide more detailed genetic inform­ation.
 
Familial DNA Searching: Identi­fying suspects by searching for genetic matches among relatives of indivi­duals in DNA databases.
Forensic Imaging:
3D Crime Scene Recons­tru­ction: Using 3D imaging technology to create accurate models of crime scenes, which can be used in invest­iga­tions and courtroom presen­tat­ions.
 
Virtual Autopsy: Non-in­vasive autopsies using imaging techno­logies like CT scans and MRIs to examine the body without tradit­ional dissec­tion.
Digital Forensics:
AI and Machine Learning: Increa­singly used to analyze large datasets, identify patterns in cyberc­rimes, and automate the process of sorting through digital evidence.
 
Blockchain Techno­logy: Being explored for use in securing digital evidence and ensuring the integrity of forensic data.
Forensic Anthro­pology:
Isotopic Analysis: Used to determine the geographic origin and dietary habits of indivi­duals based on chemical signatures in their bones and teeth.
 
Bone Micros­tru­cture Analysis: Advances in microscopy allow for detailed analysis of bone tissue to determine age, health status, and cause of death.

Case Studies in Forensic Science

The O.J. Simpson Case:
Highli­ghted the importance of proper evidence handling and the impact of forensic evidence on high-p­rofile trials. Issues with DNA evidence handling and chain of custody were central to the defense’s strategy.
The Golden State Killer:
One of the first major cases solved using familial DNA searching, leading to the identi­fic­ation and arrest of Joseph James DeAngelo decades after the crimes were committed.
The Lindbergh Kidnap­ping:
A famous early 20th-c­entury case where forensic document analysis (handw­riting analysis) played a key role in convicting Bruno Hauptmann for the kidnapping and murder of Charles Lindbergh Jr.
 

Challenges and Future Directions

Challe­nges:
Backlogs in Forensic Labora­tories: The increasing demand for forensic analysis, partic­ularly DNA testing, has led to signif­icant backlogs, delaying invest­iga­tions and trials.
 
Misuse of Forensic Science: Issues such as wrongful convic­tions due to flawed forensic testimony, reliance on unvali­dated methods, and forensic misconduct continue to challenge the field.
 
Forensic Science in Developing Countries: Limited resources, lack of trained personnel, and inadequate infras­tru­cture pose signif­icant challenges to the applic­ation of forensic science in these regions.
Future Direct­ions:
Integr­ation of Interd­isc­ipl­inary Approa­ches: Combining expertise from various scientific fields (e.g., biology, chemistry, digital sciences) to enhance forensic method­olo­gies.
 
Global Standa­rdi­zation: Efforts to standa­rdize forensic practices and method­ologies worldwide to ensure consis­tency and reliab­ility in forensic invest­iga­tions.
 
Public Engagement and Education: Increasing public unders­tanding of forensic science, its capabi­lities, and its limita­tions to counteract the miscon­cep­tions perpet­uated by popular media (e.g., the "CSI Effect­").

Conclusion

Forensic science is a critical component of the modern justice system, providing objective and scientific methods for solving crimes and delivering justice
The field continues to evolve with techno­logical advanc­ements and interd­isc­ipl­inary approa­ches, promising greater accuracy and reliab­ility in forensic invest­iga­tions
Unders­tanding the princi­ples, techni­ques, and ethical consid­era­tions of forensic science is essential for anyone involved in the criminal justice system or interested in the applic­ation of science to law