A crime scene is a location where an illegal

Law

Law is a system of rules and guidelines which are enforced through social institutions to govern behavior, wherever possible. It shapes politics, economics and society in numerous ways and serves as a social mediator of relations between people. Contract law regulates everything from buying a bus...

 act took place, and comprises the area from which most of the physical evidence

Forensic identification

Forensic identification is the application of forensic science, or "forensics", and technology to identify specific objects from the trace evidence they leave, often at a crime scene or the scene of an accident. Forensic means "for the courts"....

 is retrieved by trained law enforcement personnel

Police

The police is a personification of the state designated to put in practice the enforced law, protect property and reduce civil disorder in civilian matters. Their powers include the legitimized use of force...

, crime scene investigators (CSIs) or in rare circumstances, forensic scientists.

Evidence collection

Strictly speaking, a crime scene is a location wherein evidence of a crime may be found. It is not necessarily where the crime was committed. Indeed, there are primary, secondary and often tertiary crime scenes. For instance, the police may use a warrant

Warrant (law)

Most often, the term warrant refers to a specific type of authorization; a writ issued by a competent officer, usually a judge or magistrate, which permits an otherwise illegal act that would violate individual rights and affords the person executing the writ protection from damages if the act is...

 to search a suspect

Suspect

In the parlance of criminal justice, a suspect is a known person suspected of committing a crime.Police and reporters often incorrectly use the word suspect when referring to the...

's home. Even though the suspect did not commit the crime at that location, evidence of the crime may be found there. In another instance, an offender might kidnap at one location (primary crime scene), transport the victim (the car being a secondary crime scene), commit another crime at a distant location (murder

Murder

Murder is the unlawful killing, with malice aforethought, of another human being, and generally this state of mind distinguishes murder from other forms of unlawful homicide...

, for instance) and then dispose of the body at a fourth scene.

All locations where in there is the potential for the recovery of evidence must be handled in the same manner. They must be protected from interference of any kind so as to preserve any trace evidence

Trace evidence

Trace evidence is evidence that occurs when different objects contact one another. Such materials are often transferred by heat induced by contact friction....

. It is usually achieved by taping a wide area around the crime was committed to prevent access by any person other than the investigators. The conditions at the crime scene must be carefully recorded in great detail, as well as conserved. Only when recording has taken place can items be removed for laboratory analysis.

Legal concepts impacting the usefulness of evidence in court (Daubert, chain of custody

Chain of custody

Chain of custody refers to the chronological documentation or paper trail, showing the seizure, custody, control, transfer, analysis, and disposition of evidence, physical or electronic...

, etc.), apply to the recovery of evidence whether or not a crime actually occurred at that location.

Members of the law at a crime scene

Numerous members of the law are involved at a crime scene including police officers, crime scene investigators and forensic scientists. All who have very important roles including collection and photography of evidence.

Reconstruction

Crime scene reconstruction

Crime reconstruction

Crime scene reconstruction is the use of scientific methods, physical evidence, deductive reasoning, and their interrelationships to gain explicit knowledge of the series of events that surround the commission of a crime. It is a disciplined and principled approach towards objectively understanding...

 is the use of scientific methods, physical evidence, deductive reasoning

Deductive reasoning

Deductive reasoning, also called deductive logic, is reasoning which constructs or evaluates deductive arguments. Deductive arguments are attempts to show that a conclusion necessarily follows from a set of premises or hypothesis...

, and their interrelationships to gain explicit knowledge of the series of events that surround the commission of a crime.

External links

• International Crime Scene Investigators Association
• Association for Crime Scene Reconstruction