Discover the expert in you.
Discover the expert in you.
Electronic evidence, defined in the law enforcement community as audio, video and digital materials relevant to a crime, should be processed with the same degree of care as a unique hair or fiber sample. Replication of evidence (e.g., a DVD copy of an original video surveillance tape) immediately places its validity into doubt. For that reason, crime labs must establish well-defined procedures for collection of electronic evidence.
Corruption cases such as the 2011 trial and conviction of former New York Governor Rod Blagojevich tend to attract high profile media attention. The high profile and high stakes of corruption cases often calls for detailed and prolonged trials. Many different types of evidence are used to both prove and defend against corruption charges.
The chain of custody refers to the process used to maintain and document a record of all individuals who have had physical possession of evidence from the time it is collected until the time of trial. Strict protocol must be followed in order to maintain evidential integrity. Any lapse in the handling procedure can cause the evidence to be ruled by the court as inadmissible and may even result in charges being dismissed.
Transfer of Evidence was introduced by Edmond Locard, a criminologist at the University of Lyons in France. According to Locard's exchange principle, a criminal will always leave minute particles of evidence behind on a crime scene because wherever we go, we take something away and leave something behind. Based on this principle and advance in forensics science and modern forensic technology, crimes that were once impossible to prove can now be ascertained with remarkable conviction.
Forensic tools include any device or instrument that provides information or evidence designed to be used in a court of law. Forensic tools are used in forensic anthropology, the study of people who die in mysterious circumstances, forensic medicine and computer forensics. As technology and the methods used by criminals to evade the law become more sophisticated, portable tools that can be used in the field are becoming more popular and important for investigators.
Police are coming to rely more and more on the skills of forensic scientists to help solve crimes. From fingerprinting to DNA profiling, from blood-stained carpet fiber to ballistics analysis, the manner in which forensic evidence is collected determines how useful it will be in securing a correct criminal conviction. Collecting forensic evidence starts with carrying a "murder bag."
Maintaining the chain of custody used in digital evidence processing ensures that the evidence remains admissible in court and proves, without a doubt, who had access to the information and whether any data was altered. The chain of custody is a chronological history of the evidence that includes the origination of the evidence, documentation of each time the evidence was touched or altered and for what purpose. Digital evidence is considered volatile and requires a more detailed chain of custody to remain valid in the eyes of the court.
The National Academies of Science's 2009 report to Congress, "Strengthening Forensic Science in the United States," raised great concern in the law enforcement community. To a great extent, the public has been subjected to the "CSI effect," a reference to a popular crime drama TV show in which forensic evidence invariably finds the bad guy before the credits roll. In reality, forensic evidence is not infallible. Messy laboratory work, legal bias and the difficulty of presenting scientifically complex material to lay people all can cause problems with forensic evidence.
Trace evidence is defined as small, sometimes microscopic, particles that may be overlooked by initial investigators on the scene. This type of evidence may be extremely important in determining the sequence and existence of events that occur during a crime. Common types of trace evidence include pepper spray residue and gunshot residue. To collect pepper spray evidence, you must take samples of all of the areas that may have come in contact with the discharge from the spray can.
Forensic images are important to maintain the integrity of digital physical evidence. Research should never be done on the actual evidence because of the highly volatile nature of digital media. Each time the media is accessed, the data is changed. Simple tasks like the process of turning a computer off or on compromises the data available inside. A forensic image can be used to research data on the digital media without compromising the evidence.
The forensic rules of procedure for the collection of various types of evidence helps ensure a successful investigation and prosecution of a crime. Forensic guidelines outline appropriate rules for collecting, identifying and preserving evidence, including storing physical evidence in plastic. If investigators don't follow rules, they can contaminate evidence. When collecting tissue, organs, bones, weapons or any arson-related materials, investigators always must place these items in plastic.
Discovering and preserving computer evidence presents unique challenges. The preservation of computer evidence works a bit differently than with more tangible evidence. The destruction of computer evidence can occur as a result of actions that seem benign on the surface. Understanding how to properly preserve computer evidence can prove to be tremendously helpful in the courtroom.
Securing computer forensics evidence is a meticulous process. It requires time and patience, as details of evidence must be carefully presented at trial. Computer investigators must be licensed to run software programs which search computers for digital evidence. Maintaining the integrity of computer evidence is essential, and it must not be compromised.
Assembling the evidence for crimes in which weapons were used is a science puzzle that requires collaboration between crime scene investigators and forensic lab scientists. The weapon itself is strong evidence but there are more tests each day to identify the composition of fibers, invisible blood stains, the exact brand of a lethal or household chemical used to construct a weapon, and other evidence that can help convict a suspect of a crime.
Forensic evidence can make the difference between a jury convicting an alleged criminal or letting him go free. Investigators take great caution to carefully collect and document all evidence at a crime scene that could later be useful. Steps established by the Federal Bureau of Investigation and the investigators' own departments help make sure every piece of evidence is captured.
When a crime has been committed, police officers are required to collect anything that could be evidence related to the crime. There is a very small window of time until the hair and fibers will be disturbed. Per Douglas W. Deedrick, a unit chief for the FBI, there is a high likelihood of the transfer of fiber and hair when physical contact occurs between two people or objects, or an individual and an object. Thus, it's important that officers follow the proper collection procedures for forensic evidence.
The disappearance of a loved one is one of the most harrowing experiences a parent or relative can face. However, remaining cool, calm and collected is essential for assisting law enforcement agencies in the recovery of a missing person. With the use various forensic tools such as fingerprinting and DNA analysis, police often can track down the identity and fate of missing persons. However, they cannot do this properly without your assistance in collecting evidence.
The two major categories of evidence are physical and biological. Biological evidence, including DNA and blood, is classified as such because it comes from something or someone living. Physical evidence is nonliving and includes fingerprints, impression evidence and trace evidence. Evidence is collected and analyzed to identify suspects and solve crimes.
Forensics is a set of sciences that are employed for the investigation of civic and criminal misconduct. These sciences include a broad array of specialized fields such as DNA analysis, toxicology, ballistics and even archaeology. In that regard, the number of tools used in forensics is vast and their study and mastery require extensive training in law enforcement.
Forensic science is a general term used to describe the methods of collecting and analyzing physical evidence. Whether you are dusting and collecting fingerprints or breaking down chemical compounds to determine whether the compound is an illegal drug, you are engaged in a form of forensic science. The data obtained by forensic science are critical for the prosecution in criminal cases; they are also critical for the defense, especially if the forensic procedures were sloppy or bad.
Crime labs are run by forensic scientists who are charged with the task of comparing evidence found at the scene of a crime to evidence brought in off suspects in the crime. There are certain procedures that these scientists follow so that their findings will not be questioned in a court of law. The first procedure is for a crime scene to be protected until all evidence is found. Police will put up crime scene tape and guard the area to keep bystanders from wandering in and damaging evidence.
Forensic evidence is physical evidence that is taken from the scene of a crime and analyzed using scientific methods to aid investigators in solving a case. Such evidence is collected at a crime scene and taken to a lab, where it is processed by technicians.
