CRIME

Processing the Crime Scene for Trace Evidence

Processing the Crime Scene for Trace Evidence

Introduction

Trace evidence can be anything from massive objects to particles microscopic; which originated in the commission of a crime and it is found in crime scene or in related areas. Taking into account all available information sources in research (e.g. confessions, testimony, video surveillance), testing materials play a crucial role and especially valuable. With the exception of trace evidence, all other sources of information raise questions of limited reliability. When tests are recognized and manipulate materials adequately provide the best prospects of providing objective information and reliable information on the incident under investigation. However, even the value of the evidence recovered with great care and better preserved may be lost if not properly maintained chain of custody.

It is often considered the chain of custody is the weak point of the research criminals. It means the chronological and thorough documentation of evidence to establish their links with the alleged crime. From start to finish forensic process is crucial to demonstrate each measure to ensure the "traceability" and "continuity" of the evidence from the scene crime to the courtroom.

Forensic DNA testing originated in the United Kingdom. In the first use of DNA in a criminal investigation in the UK, analysis of a DNA sample from a man confessing to the second of two rapes and murders that occurred in rural Leicestershire suggested that he was not the offender. The DNA samples from the rape victims showed that the offences had been perpetrated by the same individual. In January 1987, police proceeded to collect DNA samples from all the males aged between 16 and 34 years in three local villages. None of the 5500 collected samples matched the crime stains. However, months later, police were notified that one man had given a sample on behalf of a colleague, Colin Pitchfork. Both men were arrested and DNA testing revealed that Pitchfork's sample matched the crime scene samples. Pitchfork confessed and was convicted in January 1988 (Walker and Cram 1990: 480).

In due course, the United Kingdom became the first country to develop a large-scale DNA database for the purpose of criminal investigation (Peterson 2000). Although it is now less extensive than the CODIS database in the United States, the UK national DNA database (NDNAD) remains much larger than comparable databases in other European countries. Between 1987 and 2005, the expansion (in both size and scope) of the NDNAD occurred piecemeal, and was largely regarded as a reflection of police operational concerns.

In the United States, a national DNA database (managed through the CODIS software, the Combined DNA Index System) was developed by the FBI in 1998. The database was developed as a result of the 1994 DNA Identification Act, which granted the FBI authorization to create a national DNA database using four main sources: 'persons convicted of crimes, samples recovered from crime scenes, samples recovered from unidentified human remains, and samples voluntarily contributed by relatives of missing persons' (Stevens 2001: ...