The role of forensic chemistry in criminal investigations

Forensic Chemistry

Forensics is a very important part of a crime scene investigation. There used to be a time when murders or crimes were left unsolved due to the lack of evidence. However with the advances in technology and research in forensics, crime solving has become a lot easier. The branch of science, which helps out in finding out important evidence, is known as Forensics Chemistry. Forensics Chemistry employs methods, which help in finding clues, which couldn't be found in any other circumstances. We can simply call it the application of a brand of chemistry at the scene of a crime. This is a science which helps us investigate chemical substances and can help trace the cause of the death of a human being by finding useful evidence. However it's not important that the crime scene may be a site of murder or theft. It could also be due to environmental factors by a corporation, hazardous working conditions from an industrial area or tainted food from a restaurant. With the help of forensic chemistry the cause of death is easily classified into a category.

The evidence could be both biological as well as inorganic. Biological evidence consists of anything (blood, bodily fluids, hair, etc.) while inorganic substances could be traces of poisonous substances, gunpowder residue, etc.

Forensic Evidence

It's the job of a Senior Forensic Chemist to be responsible for the proper handling of the forensic chemistry work. This involves the careful handling of the substances, which are seized from the scenes of a crime by law enforcement officials. The chemist has to apply a proper level of analysis, as it's a highly complex matter, which doesn't have any room for errors. If there is the presence of anything like "blood, gun, fingerprints, semen, hair, fiber, handwriting, shoe impression, DNA, or a tooth mark" then a forensic chemist can use scientific tools to find out the cause of the murder and the person responsible for it.

Cause of Death

Experts in forensic chemistry are known as Forensic Chemists. They have to be present on the scene of a crime to identify the unknown substances. With their knowledge they can find out about the cause of death of a person. If a person has been poisoned a test is run to check for toxins in the blood. If there is a presence of nitrates in the skin, it indicates whether or not someone has fired a gun. Forensic chemistry plays an important part in criminal justice. A lot of crimes have been solved with the help of forensics chemistry. Analytic chemistry is closely linked with forensic chemistry because the latter uses the former in legal situations.

One of the most prominent ways of tracing the cause of the crime is the application of DNA profiling.

Ink Dating

One of the other ways to do a forensic test is known as the Ink Dating test. It is used to find out when the ink was written on a document. This is a useful tool as it can tell a lot about the time of entries made in medical records, bills, wills and notes and diaries. Due to the advances in technology ink dating can be done within 6 months. The dating of ink can be done in two ways; chemical composition is one of them. This can help find out about the authenticity of an older document. With the help of ink dating documents can be dated. The second way is to use the rate of extraction in a paper. This method finds out how fast ink can be removed from a paper through chemical means. If the paper is new the ink is removed faster. If it's old then it takes some time for the paper to be removed.

Legal Validity

The scientific quarters as well as the judicial system have questioned its validity. Due to its scientific nature a lot of questions have been raised especially by the privacy rights advocacy. According to them, the privacy rights of suspects would be violated after being DNA profiled. Suspects would have to surrender body tissue samples to be used in the information. Then there was the issue of who would control the DNA bank. The Australian Legal system needs to have some laws which would protect an individual's privacy while at the same time allows them access to the technology which would single out the innocent from the guilty. This is one of the most important issues facing the Australian courts and investigators. According to Australian law it was hard to accept DNA profiling as part of the evidence as it could be flawed. The use of DNA as evidence can be flawed as it can be tampered with in some cases. However with the advances in technology and the employment of new methods, the legal system has come to terms with the inclusion of scientific evidence in trials. So there have been of cases where DNA evidence has been allowed as part of the trial.

In Australia, profiling used to be done by private companies and now includes state forensics laboratories. There have been cases in Australia where the defendants have been caught due to the matching of the profile of the data. In some cases samples taken from suspects were against their own will, which caused a furor as it questioned the civil liberties of the suspect. (Reform 1989; Scutt 1990; Coelli 1989)

DNA evidence was submitted in three criminal cases in Australia. It was challenged in two of those cases but it was found that the DNA evidence was admissible. However there have been cases where DNA wasn't admissible as it was found not to be treated with care. The evidence had not been handled carefully due to sloppy work. Due to that the evidence was not admissible. In another case the investigator had accidentally sneezed over the evidence, which made it hard for the forensics department to track the culprit.