Analyzing the Crime Scene Chapter 2 Forensic Science bsapp.com

Approaching a Crime Scene bsapp.com

Approaching a Crime Scene Personal Safety and the well being of victims is paramount. Personal Safety and the well being of victims is paramount. Secure / Preserve and Isolate the crime scene. Video Secure / Preserve and Isolate the crime scene. VideoVideo Record the crime scene in photos, sketches and notes. Record the crime scene in photos, sketches and notes. bsapp.com

Recording the Crime Scene Photographs /videos Photographs /videosvideos Software. Software. Software Sketches Sketches Notes Notes Notes bsapp.com

Rough Sketch of the Crime Scene The initial documentation of the crime scene. The initial documentation of the crime scene. Often a hand drawn representation of the scene by investigators. Often a hand drawn representation of the scene by investigators.

Rough Sketch to Final bsapp.com A computer drawn CAD version of the combination of the rough sketch and notes from the investigators.

Notes Match to sketch Match to sketch Use a numbered key Use a numbered key Quick, short, bulleted Quick, short, bulleted What can you not see from the photo? What can you not see from the photo? Critical Observations of the scene. Use all senses. Critical Observations of the scene. Use all senses. bsapp.com

Photography Scene Scene Multiple views Multiple views Entrances Entrances Exits Exits Windows Windows  Evidence  Close ups  Perspectives  Multiple angles bsapp.com Different Wavelengths of photography: IR or UV

Collecting Evidence Victim's clothing Victim's clothing Fingernail scrapings Fingernail scrapings Head and pubic hairs Head and pubic hairs Blood (for typing purposes) Blood (for typing purposes) bsapp.com VideoVideo FBI training film

Vaginal, anal, and oral swabs Vaginal, anal, and oral swabs Recovered bullets from the body and/or surrounding area Recovered bullets from the body and/or surrounding area Hand swabs or washings from shooting victims Hand swabs or washings from shooting victims bsapp.com

Chain of Custody Chain of custody (CoC), in legal contexts, refers to the chronological documentation or paper trail, showing the seizure, custody, control, transfer, analysis, and disposition of physical or electronic evidence. Chain of custody (CoC), in legal contexts, refers to the chronological documentation or paper trail, showing the seizure, custody, control, transfer, analysis, and disposition of physical or electronic evidence. paper trailevidence paper trailevidence Particularly important in criminal cases, the concept is also applied in civil litigation – and sometimes more broadly in drug testing of athletes, traceability of food products and to provide assurances that wood products originate from sustainably managed forests. Particularly important in criminal cases, the concept is also applied in civil litigation – and sometimes more broadly in drug testing of athletes, traceability of food products and to provide assurances that wood products originate from sustainably managed forests.traceabilitysustainably managed foreststraceabilitysustainably managed forests

Police Sketches of Criminals Police sketch artists will convert a victim or eyewitness description to a depiction of the suspect. Police sketch artists will convert a victim or eyewitness description to a depiction of the suspect. Video Video Video

Level Types of Evidence: Class or Individual Class level evidence is a characteristic of evidence that points to a group of objects or people. Example: new tennis shoes… that lots of people could have. Class level evidence is a characteristic of evidence that points to a group of objects or people. Example: new tennis shoes… that lots of people could have. Individual level evidence is a characteristic of evidence that pinpoints a singular person or object. Example: DNA Individual level evidence is a characteristic of evidence that pinpoints a singular person or object. Example: DNA Video Video Video

Crime Scene Evidence There are many different types of evidence found at a crime scene. Any of these could be a significant piece in solving the crime. The significance of each piece of evidence is often unknown until after the evidence has been bagged, labeled, and sent to the lab. There are many different types of evidence found at a crime scene. Any of these could be a significant piece in solving the crime. The significance of each piece of evidence is often unknown until after the evidence has been bagged, labeled, and sent to the lab. For these reasons, forensic scientists treat each and every piece of evidence as if it is vital. Every object at a crime scene is considered to be significant until toughly examined. For these reasons, forensic scientists treat each and every piece of evidence as if it is vital. Every object at a crime scene is considered to be significant until toughly examined.

Types of Analysis Comparison : Most types of evidence require a control with which to be compared (example: fingerprints, hairs) Comparison : Most types of evidence require a control with which to be compared (example: fingerprints, hairs) Visual : vidence that can be utilized or compared through unaided observation, (example: fingerprints, tool marks) Visual : Evidence that can be utilized or compared through unaided observation, (example: fingerprints, tool marks) Microscopic (trace) analysis that evidence that must be observed with the use of some type of microscope (example: hairs, fibers) Microscopic (trace) analysis that evidence that must be observed with the use of some type of microscope (example: hairs, fibers) Chemical If an article of evidence must be subjected to chemical analysis (example: DNA typing, drug screening). Can be Trace Evidence Chemical : If an article of evidence must be subjected to chemical analysis (example: DNA typing, drug screening). Can be Trace Evidence

Common Types of Physical Evidence Documents. Documents. Any document, handwritten or printed, will be submitted so that authenticity and source can be determined. These types of analysis are utilized mainly with ransom notes, suicide notes, death threats, and forgeries. Glass. Glass panes, particles, or fragments that are found or transferred to a person or object involved in a crime may be substantial evidence. Such evidence, whether broken by a bullet or fingerprints, may link a suspect or piece of evidence to a crime scene, and be used to deduce cause of breakage or direction of penetration. Glass. Glass panes, particles, or fragments that are found or transferred to a person or object involved in a crime may be substantial evidence. Such evidence, whether broken by a bullet or fingerprints, may link a suspect or piece of evidence to a crime scene, and be used to deduce cause of breakage or direction of penetration. Fingerprints a mainstay in criminal investigating. When a person touches an article with their bare hands that a print is left behind. Such prints are called latent prints. with the utilization of computers and large databases, identifying a suspect’s prints have become routine. Fingerprints a mainstay in criminal investigating. When a person touches an article with their bare hands that a print is left behind. Such prints are called latent prints. with the utilization of computers and large databases, identifying a suspect’s prints have become routine.

Common Types of Physical Evidence Hairs are often found at a crime scene and are fairly easy to compare and identify with the use of a microscope. Any animal or human hair present at the scene could link a person or animal with a crime. With a number of samples to compare, hairs from a crime scene may be matched to a suspect with a high degree of certainty. Upon the discovery of a root or follicle tissue, DNA analysis can provide an exact match. Hairs are often found at a crime scene and are fairly easy to compare and identify with the use of a microscope. Any animal or human hair present at the scene could link a person or animal with a crime. With a number of samples to compare, hairs from a crime scene may be matched to a suspect with a high degree of certainty. Upon the discovery of a root or follicle tissue, DNA analysis can provide an exact match. Body or parts are often found in scenes that involve the most serious of crime. DNA, Anthropology, Odontology can reveal the identity. Body or parts are often found in scenes that involve the most serious of crime. DNA, Anthropology, Odontology can reveal the identity.

Common Types of Physical Evidence Soils, Minerals, Wood, and Other Vegetative Matter. Any items containing soil, minerals, wood, or other vegetative matter could link a person or object to a particular location (for example, soil imbedded in shoes and vault insulation found on garments). Soils, Minerals, Wood, and Other Vegetative Matter. Any items containing soil, minerals, wood, or other vegetative matter could link a person or object to a particular location (for example, soil imbedded in shoes and vault insulation found on garments). Fibers are any natural or synthetic fiber transferred which may be useful in establishing a relationship between objects and/or persons. They may be able to predict if such a fiber originated from clothes, towels, carpet, or other sources. Fibers are any natural or synthetic fiber transferred which may be useful in establishing a relationship between objects and/or persons. They may be able to predict if such a fiber originated from clothes, towels, carpet, or other sources.

Common Types of Physical Evidence Firearms as well as ammunition, are often important evidence in an investigation. In fact, it is often impossible to get a conviction in shooting cases without the discovery of such evidence. Firearms as well as ammunition, are often important evidence in an investigation. In fact, it is often impossible to get a conviction in shooting cases without the discovery of such evidence. Powder Residue. Powder Residue. A person or item may be suspected of containing firearm discharge residue. The presence and disbursement of powder residue is used to discern if, when, and where a firearm may have been fired.

Common Types of Physical Evidence Explosives and petroleum products. These products are devices containing an explosive charge, as well as all objects removed from the scene of an explosion or fire that are suspected to contain the residues of an explosive material. The placement and appearance of these items is significant in determining where a fire or explosion originated and advanced. After collection and analysis, the chemical composition of such may be helpful identifying the origin and users of the substances. Explosives and petroleum products. These products are devices containing an explosive charge, as well as all objects removed from the scene of an explosion or fire that are suspected to contain the residues of an explosive material. The placement and appearance of these items is significant in determining where a fire or explosion originated and advanced. After collection and analysis, the chemical composition of such may be helpful identifying the origin and users of the substances. Video

Common Types of Physical Evidence Impressions and Tool Marks. Impressions include tire markings, shoe prints, depressions in soft soils, and all other forms of tracks, glove and fabric impressions, and bite marks in skin or foodstuffs. Impressions and Tool Marks. Impressions include tire markings, shoe prints, depressions in soft soils, and all other forms of tracks, glove and fabric impressions, and bite marks in skin or foodstuffs. Drugs. Any substance in violation of laws regulating the sale, manufacture, distribution, and use of drugs or chemicals will be seized. Drugs. Any substance in violation of laws regulating the sale, manufacture, distribution, and use of drugs or chemicals will be seized. In addition to the large number of illegal drugs which are manufactured, sold, and used, a large number of perpetrators committing other crimes In addition to the large number of illegal drugs which are manufactured, sold, and used, a large number of perpetrators committing other crimes

Common Types of Physical Evidence Paint. Any paint, wet or dry, may be transferred from the surface of one object to another during the perpetration of a crime. Most paint evidence originates from crimes involving hit-and-runs. With a control sample to compare a suspected sample, paint can be matched to a vehicle with near 100% certainty. Paint. Any paint, wet or dry, may be transferred from the surface of one object to another during the perpetration of a crime. Most paint evidence originates from crimes involving hit-and-runs. With a control sample to compare a suspected sample, paint can be matched to a vehicle with near 100% certainty. Blood, Semen, Saliva, Organs, and other Physiological Fluids. All body fluids, animal or human, will be subjected to biochemical analysis for determination of identity and origin. By examining the amount, color, and distribution of such fluids, an investigator may able to make several predictions about what took place at a scene. Blood, Semen, Saliva, Organs, and other Physiological Fluids. All body fluids, animal or human, will be subjected to biochemical analysis for determination of identity and origin. By examining the amount, color, and distribution of such fluids, an investigator may able to make several predictions about what took place at a scene.

Collecting Evidence Bag & Tag evidence according to standard operating procedures College class example video College class example video bsapp.com

Collecting Controls Controls are samples that help eliminate the innocent bystanders and those not considered as suspects. They include fingerprints, DNA Samples, Hair, and other evidence from possible suspects or victims for comparison to evidence. Controls are samples that help eliminate the innocent bystanders and those not considered as suspects. They include fingerprints, DNA Samples, Hair, and other evidence from possible suspects or victims for comparison to evidence. bsapp.com

Search Warrants A search warrant is a court order issued by a magistrate, judge or Supreme Court official that authorizes law enforcement officers to conduct a search of a person, location, or vehicle for evidence of a crime and to confiscate evidence if it is found. A search warrant cannot be issued in aid of civil process. A search warrant is a court order issued by a magistrate, judge or Supreme Court official that authorizes law enforcement officers to conduct a search of a person, location, or vehicle for evidence of a crime and to confiscate evidence if it is found. A search warrant cannot be issued in aid of civil process.

When is a Warrant Required for Evidence Collection? The Fourth Amendment to the United States Constitution protects Americans from unreasonable searches by the government. That means that absent an emergency situation or other legal exception, a police officer must have a search warrant before conducting a search of your person or property. The Fourth Amendment to the United States Constitution protects Americans from unreasonable searches by the government. That means that absent an emergency situation or other legal exception, a police officer must have a search warrant before conducting a search of your person or property.

How to Get a Warrant? A judge will only approve a search warrant if law enforcement is specific as to the items and location it wishes to search. Law enforcement must also prove that probable cause exists that a specific item is located in a specific place. A judge will only approve a search warrant if law enforcement is specific as to the items and location it wishes to search. Law enforcement must also prove that probable cause exists that a specific item is located in a specific place. Whether the warrant gets issued or not is up to the judge's review. If a judge finds that law enforcement has met its burden of probable cause and has included enough specificity in the request for the warrant, then the judge will issue the search warrant. Whether the warrant gets issued or not is up to the judge's review. If a judge finds that law enforcement has met its burden of probable cause and has included enough specificity in the request for the warrant, then the judge will issue the search warrant.

When is Search Warrant NOT Necessary? Consent: Law enforcement can request to enter a person’s home or search a person’s belongings Plain View Doctrine: Law enforcement does not need a search warrant to obtain evidence that is in plain sight. Emergency Situation: If the police are in hot pursuit of a felon and follow that alleged felon into a home or other private area then they do not need a warrant to obtain evidence that is in plain sight when they enter the building. Search Incident to Arrest: Police officers may search the body and immediate surroundings of a person whom they take into custody.

Review of the Crime Scene Analysis Video Video Video