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Criminology

Forensic science (often shortened to forensics) is the application of a broad spectrum of sciences to answer questions of interest to the legal system. This may be in relation to a crime or to a civil action. But besides its relevance to the underlying legal system, more generally forensics encompasses the accepted scholarly or scientific methodology and norms under which the facts regarding an event, or an artifact, or some other physical item (such as a corpse, or cadaver, for example) are ascertained as being the case. In that regard the concept is related to the broader notion of authentication whereby an interest outside of a legal form exists in determining whether an object is in fact what it purports to be, or is alleged as being. The word “forensic” comes from the Latin adjective “forensis” meaning of or before the forum. During the time of the Romans, a criminal charge meant presenting the case before a group of public individuals in the forum. Both the person accused of the crime and the accuser would give speeches based on their side of the story. The individual with the best argument and delivery would determine the outcome of the case. Basically, the person with the sharpest forensic skills would win. This origin is the source of the two modern usages of the word “forensic” – as a form of legal evidence and as a category of public presentation. In modern use, the term “forensics” in place of “forensic science” can be considered incorrect as the term “forensic” is effectively a synonym for “legal” or “related to courts”. However, the term is now so closely associated with the scientific field that many dictionaries include the meaning that equates the word “forensics” with “forensic science”.

Forensic Anthropology

Forensic anthropology is the application of the science of physical anthropology and human osteology (the study of the human skeleton) in a legal setting, most often in criminal cases where the victim’s remains are more or less skeletonized. A forensic anthropologist can also assist in the identification of deceased individuals whose remains are decomposed, burned, mutilated or otherwise unrecognizable. The adjective “forensic” refers to the application of this subfield of science to a court of law.

Forensic anthropology borrows methods developed from the academic discipline of physical anthropology and applies them to cases of forensic importance. These techniques can be used to assess age, sex, stature, ancestry, and analyze trauma and disease. Forensic anthropologists frequently work in conjunction with forensic pathologists, odontologists, and homicide investigators to identify a decedent, discover evidence of trauma, and determine the postmortem interval. Though they typically lack the legal authority to declare the official cause of death, their opinions may be taken into consideration by the medical examiner. They may also testify in court as expert witness, though data from some of the techniques commonly used in the field—such as forensic facial reconstruction—are inadmissible as forensic evidence.

Questioned Document Examination

Questioned document examination (QDE) is known by many names including forensic document examination, document examination, diplomatics, handwriting examination, and sometimes handwriting analysis, although the latter name is not often used as it may be confused with graphology. Likewise a forensic document examiner is not to be confused with a graphologist, and vice versa. The questioned document division of a crime lab is sometimes referred to as “QD” in popular media.

The task of forensic document examination is to answer questions about a disputed document using a variety of scientific processes and methods. Many examinations involve a comparison of the questioned document, or components of the document, to a set of known standards. The most common type of examination involves handwriting wherein the examiner tries to address concerns about potential authorship.

One task of a forensic document examiner is to determine if a questioned item originated from the same source as the known item(s), then present their opinion in court as an expert witness. Other tasks include determining what has happened to a document, determining when a document was produced, or deciphering information on the document that has been obscured, obliterated or erased.

Forensic Psychology

Forensic psychology is the intersection between Psychology and the legal system. It is a division of applied psychology concerned with the collection, examination and presentation of psychological evidence for judicial purposes.

The practice of forensic psychology involves understanding applicable law in the relevant jurisdictions in order to be able to make legal evaluations and interact appropriately with judges, attorneys and other legal professionals. An important aspect of forensic psychology is the ability to testify in court, reformulating psychological findings into the legal language of the courtroom to provide information to legal personnel in a way that can be understood. Further, in order to be a credible witness, for example in Canada, the forensic psychologist must understand the philosophy, rules and standards of the American judicial system, as well as display competency in psychological practice. Primary is an understanding of the adversarial model under which the system functions. Lack of a firm grasp of these procedures will result in the forensic psychologist losing credibility in the courtroom.

Forensic Toxicology

Forensic toxicology is the use of toxicology and other disciplines such as analytical chemistry, pharmacology and clinical chemistry to aid medicolegal investigation of death, poisoning, and drug use. The primary concern for forensic toxicology is not the legal outcome of the toxicological investigation, but rather the technology and techniques for obtaining and interpreting the results. A toxicological analysis can be done to various kinds of samples.

A forensic toxicologist must consider the context of an investigation, in particular any physical symptoms recorded, and any evidence collected at a crime scene that may narrow the search, such as pill bottles, powders, trace residue, and any available chemicals. Provided with this information and samples with which to work, the forensic toxicologist must determine which toxic substances are present, in what concentrations, and the probable effect of those chemicals on the person.

Determining the substance ingested is often complicated by the body’s natural processes, as it is rare for a chemical to remain in its original form once in the body. For example: heroin is almost immediately metabolized into another substance and further to morphine, making detailed investigation into factors such as injection marks and chemical purity necessary to confirm diagnosis. The substance may also have been diluted by its dispersal through the body; while a pill or other regulated dose of a drug may have grams or milligrams of the active constituent, an individual sample under investigation may only contain micrograms or nano-grams.

Forensic Ondontology

I have never talked about forensic odontology before so I thought I’d talk a bit about it.

Forensic dentistry or forensic odontology is the proper handling, examination and evaluation of dental evidence, which will be then presented in the interest of justice. The evidence that may be derived from teeth, is the age (in children) and identification of the person to whom the teeth belong. This is done using dental records or antemortem (prior to death) photographs. Forensic odontology is derived from latin, meaning forum or where legal matters are discussed. The first forensic dentist in the United States was Dr. Paul Revere who was known for the identification of fallen revolutionary soldiers.

The other type of evidence is that of bite marks, left on either the victim (by the attacker), the perpetrator, or on an object found at the crime scene. Bite marks are often found on children who are abused.

Forensic dentists are responsible for six main areas of practice:

* Identification of found human remains
* Identification in mass fatalities
* Assessment of bite mark injuries
* Assessment of cases of abuse (child, spousal, elder)
* Civil cases involving malpractice
* Age estimation

- Brandon Anderson

Ballistics: the basics

Many People ask me about ballistics and most of those questions are the simple one’s, e.g., how is a bullet fired from a firearm? So I thought I’d tell you all the answer. First i’ll start off by telling you that some bullets may be different in shape, size, and weight but the are all constructed generally the same. A bullet has five main parts the bullet itself, the bullet casing, the propellent, the rim, and the primer. Here’s an overview of how a bullet is fired, when the firing pin of the firearm hits the primer it makes a tiny explosion that ignites the propellent (gun powder) inside the bullet casing thus propelling the bullet  out of the barrel of the firearm.
Bullets can be matched to other bullets found at a crime scene or test fired at a crime lab, by looking trough a microscope at the fired bullets side by side you can see very fine striations left on the bullet when it was propelled out of the firearm, these striations are unique just like a fingerprint is and can be matched to one and other. Another way of matching bullet is by looking at the shell casing, provided you have the shell casing of course, and looking a the primer of a test fired bullet casing and one found at a crime scene if they are a match the area on the primer where the firing pin hit they will be the same and again these are unique.

- Brandon Anderson

Decomposition

Decomposition refers to the reduction of the body of a formerly living organism into simpler forms of matter. The body of a living organism begins to decompose shortly after death. Such decomposition can be simplified in two stages: In the first stage, it is limited to the production of vapors. In the second stage, liquid materials form and the flesh or plant matter begins to decompose.

There are environmental influences that will affect decomposition. A body that is exposed to air will decompose more quickly and will have more insect activity. A buried body will decompose eight times slower than a body exposed to air. This is due in part to limited insect activity and possibly lower temperatures. Likewise a body submerged in water decomposes at half the rate of an exposed body. The rate of decomposition depends on the temperature of the water. Cold water will allow slow decomposition and warm water causes faster decomposition. The body is also shielded from insect activity as long as it is submerged.

Rigor, Livor, and Algor Mortis: what is it and how is it useful to forensic investigators

Rigor Mortis,

Rigor Mortis is one of the recognizable signs of death that is caused by a chemical change in the muscles after death, causing the limbs of the corpse to become stiff. The body’s muscles may contract in seemingly random and bizarre ways even though the body is dead. After a muscle contracts, ATP expenditure is required to release the myosin head of a thick filament from its binding site on the thin filament. Since all metabolic processes have come to a halt  in a dead body, no ATP is produced, they become “stiff and locked” into place.

Livor Mortis

Livor mortis or postmortem lividity or hypostasis is the setting of blood in the lower portion of the body, causing a purplish red discoloration of the skin, when the heart is no longer agitating the blood, heavy red blood cells sink through the serum by action of gravity. This discoloration does not occur in the areas of the body that are in contact with the ground or another object, as the capillaries are compressed. Coroners can use the presence or absence of livor mortis as a means of determining an approximate time of death. It can also be used by forensic investigators to determine whether or not a body has been moved (for instance, if the body is found lying face down but the pooling is present on its back, investigators can determine that the body was originally positioned face up). Livor mortis starts 20 minutes to 3 hours after death and is congealed in the capillaries in 4 to 5 hours. Maximum lividity occurs within 6-12 hours.

Algor Mortis

Algor mortis is the reduction in body temperature following death. This is generally a steady decline until matching ambient temperature, although external factors can have a significant influence. As decomposition occurs the internal body temperature tends to rise again.

What Exactly is Forensic Science?

I’ve gotten many e-mails asking what is forensics anyway so here you go, forensics the shortened term for forensic science is the application of a broad spectrum of sciences to answer questions of interest to the legal system.
The word “forensic” comes from the Latin adjective “forensis” meaning of or before the forum.

Entomology: timeline

Flies and maggots can provide an approximate time of death, there very useful for cases where the body has been deceased for a long time. Only certain insects will feed and lay eggs on a dead corpse forensic entomologists study these insects, and their larvae cycles can determine whether a body has been dead for one day or three or four weeks

Documentation Procedures

Many law enforcement agencies use a variety of preprinted documents or forms, designed to record certain aspects of crime scene investigation. These documents normally have resulted from a trial-and-error approach based on actual case experiences. Despite variations in the design of these documents, the purpose and goals behind their use are usually identical from one agency to another. 

There is an important point to consider when forms, are being drafted for routine use. Often, there is a tendency to regard forms as means to cover every possibility that personnel may confront, such documents normally serve only as reminders of the minimum pertinent information needed to perform a task. Each scene will require some? L of deviation from the norm, based on the complexities at hand. Forms are not substitutes for thinking; they are merely tools to assist personnel to fully exercise training and experience to meet the needs of a given situation. 

There are normally six important categories of documentation that are considered applicable to any search:

John Doe, Jane Doe: what’s that about

John and Jane Doe is a name to a person whose true identity is unknown, child’s or baby whose identity is unknown can be referred to as a Baby Doe. Additional people in the same family may be called James Doe, Judy Doe, etc.

Fingerprint Classification

Just as we would classify food in categories of fruit, dairy, vegetables, and meat forensic scientists classify fingerprints in categories: arch, tented arch, right loop, left loop, whorl, twin loop in the image below are photos of fingerprints and how they are classified.
a) arch
b) tented arch
c) right loop
d) left loop
e) whorl
f) twin loop

Why do we classify fingerprints this way?

For example there are 12 fingerprints collected from a crime scene and there are only two of them that are arches and  we are trying to match at least one to a suspect, and the suspect has a arch fingerprint. It would be tedious work to try to match all the prints to one print when we know there are only two prints that are arches and the suspect has an arched fingerprint.

DNA – Deoxyribonucleic Acid

DNA, Deoxyribonucleic acid

DNA is a huge but fun topic, so ill start with an introduction DNA is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms and some viruses. The main role of DNA molecules is the long-term storage of information. DNA is often compared to a set of blueprints, since it contains the instructions needed to construct other components of cells, such as proteins and RNA molecules. The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in regulating the use of this genetic information.

Forensics and DNA

Forensic Scientists can use DNA in blood, semen, skin, saliva or hair at a crime scene to identify a perpetrator. This process is called genetic fingerprinting, or more accurately, DNA profiling. In DNA profiling, the lengths of variable sections of repetitive DNA, such as short tandem repeats and minisatellites, are compared between people. This method is usually an extremely reliable technique for identifying a criminal. However, identification can be complicated if the scene is contaminated with DNA from several people. DNA profiling was developed in 1984 by British geneticist Sir Alec Jeffreys,and first used in forensic science to convict Colin Pitchfork in the 1988 Enderby murders case. People convicted of certain types of crimes may be required to provide a sample of DNA for a database. This has helped investigators solve old cases where only a DNA sample was obtained from the scene. DNA profiling can also be used to identify victims of mass casualty incidents.

Entomology: the blowfly

The life cycle of the fly, Fly to Egg to Larvae to Pupae and the cycle continues. The most common fly in forensic homicide investigation’s is the blowfly.

After one hour of death the blowfly will appear then the blowfly’s lay there eggs in a moist area. Then the eggs hatch into larvae -usually reaching a length of a half an inch. After the first 3 days. After the next 6-10 days the larvae feed and grow and repeatedly molt and finally Pupae. When their outer casing hardens. Approximately 12 days later adult blowflies emerge, and the cycle continues.

The problem with entomology can be inaccurate because of climate conditions, weather, temperature, place ect. But most of the time entomology clustered together with autopsy reports and crime scene temperatures can tell you a lot.

Arson-What Influences

A lot of thing can influence a person to commit arson (criminal damage act). Usually its to cover up a murder but that isn’t helpful; because human bones don’t fully burn up into dust. And that can leave behind important evidence that can help solve a case. For example someone was stabbed with a knife the knife marks between two rib bones can identify the length, width and sometimes the type of knife just by the marks on the bones. Another example would be Rage, or even for fun. and a thing that scary even firefighters have been known to start commit arson for gratification for example firefighters would set fires and then go in and save the people in side. And even if there’s a lack of fires firefighters will go an commit arson. But you can rest assured that a firefight probably won’t commit arson it is very rare for this to happen.

Pursuing a Career in Forensics

Thinking about pursuing a career in forensics but don’t want to deal with blood and dead bodies. Well here are some careers without that, Computer forensics, Forensic art, DNA technician (although you may encounter some blood),Ballistics (a person who works with bullets and guns) and if you don’t mind blood and dead bodies here are some careers you may like Forensic investigator, Crime scene investigator, and Criminologist. Below are two websites to help you learn more

1.www.communitycollegelistings.com/college-search-pre-planning.aspx

2.www.allcriminaljusticeschools.com/featured/forensic-science/?src=goo_forensics_colleges3b

Blood Spatter Catagories Continued

Transfer/Contact bloodstains A transfer or contact stain is produced when an object with blood comes in contact with an object or surface that does not have blood. It may be possible to discern the object that left the blood impression. Wipe Pattern – A bloodstain pattern created when an object moves through an existing stain, removing and/or altering its appearance. Swipe Pattern – The transfer of blood from a moving source onto an unstained surface. Direction of travel may be determined by the feathered edge. As indicated above, there are other terms currently used in BPA and different ways of classifying bloodstain patterns. For example there is a debate over the misnomer of the LVIS, MVIS, and HVIS as it relates to the physical term ‘’velocity’’. A sub-committee of the SWGSTAIN has been tasked with addressing the terminology issues and develop a taxonomy for bloodstain patterns.

Low velocity impact spatter Low velocity impact spatter (LVIS) is generally produced when objects traveling less than 1.5 m/s come in contact with a blood source. The preponderance of stains is generally larger than 3 mm in diameter.

Medium velocity impact spatter Medium velocity impact spatter (MVIS) is generally produced when objects traveling between 1.5 m/s and 7.5 m/s come in contact with a blood source. The preponderance of stains is generally between 1 mm and 3 mm in diameter. Mechanisms that could produce this type of pattern include blunt force trauma or cutting/stabbing actions.

High velocity impact spatter High velocity impact spatter (HVIS) is generally produced when objects traveling greater than 30 m/s come in contact with a blood source. The preponderance of stains is generally smaller than 1 mm in diameter. This pattern often has a mist-like appearance. High velocity patterns may be created by gunshots or explosives, but may also be caused by industrial machinery, coughing, or sneezing.

Blood Spatter Catagories

Passive bloodstains Passive bloodstains are those stains created by the force of gravity. Passive Drop – Bloodstain drop(s) created or formed by the force of gravity acting alone. Drip Pattern – A bloodstain pattern which results from blood dripping into blood. Flow Pattern – A change in the shape and direction of a bloodstain due to the influence of gravity or movement of the object. Pool Pattern – A bloodstain pattern formed when a source of blood is stationary for a period of time.

Projected bloodstains A projected stain occurs when some form of energy has been transferred to a blood source. Low Velocity Impact Spatter (LVIS) – A bloodstain pattern that is caused by a low velocity impact\force to a blood source. Medium Velocity Impact Spatter (MVIS) – A bloodstain pattern caused by a medium velocity impact\force to a blood source. A beating typically causes this type of spatter. High Velocity Impact Spatter (HVIS) – A bloodstain pattern caused by a high velocity impact\force to a blood source such as that produced by gunshot or high-speed machinery. Cast-Off Pattern – A bloodstain pattern created when blood is released or thrown from a blood-bearing object in motion. Arterial Spurting (OR Gushing) Pattern – Bloodstain pattern(s) resulting from blood exiting the body under pressure from a breached artery. Back Spatter – Blood directed back towards the source of energy or force that caused the spatter. Expiratory Blood – Blood that is blown out of the nose, mouth, or a wound as a result of air pressure and/or air flow which is the propelling force.

Fingerprinting

 Fingerprinting, i’ve learned that fingerprinting can be done by just about anyone. Fingerprinting is not hard if you know the technique that being, Holding the fingerprint brush at a slight 45 degree angle and using a spinning motion rather than a sweeping motion. Now you need powder you can get finger printing kits at sciences stores or you can get a children’s finger print kit from a toys r us which work the same. or you can buy baby powder(talcum powder) and by going to a printer store you can get ink powder which works all the same. for a brush to get a good proper one you can buy it of the Internet. but anyway here’s ho you do it put the brush into a jar of powder the techniques the same for all colors of powder and gently twirl the brush around until a print appears then blow the extra powder off with a mechanical blower not your mouth because saliva can hit the print and wreck it. Then using wide clear scotch tape and gently apply the tape with you pinkie and then peal the tape off not to fast and no to slow then put the tape on a white or black piece of paper depending on the color of powder.