Shouldn't we create a DNA database for criminals?

Deoxyribonucleic acid (DNA), the main constituent of the chromosome of all organisms is found in the double helix form within the nucleus of every somatic cell. Thus, a small sample of human body cells can be used to reveal the genetic pattern of an individual. The DNA of an individual does not change during his lifetime in normal condition and the technique is commonly used in developed countries and is termed 'DNA- fingerprinting'.

DNA analysis for clinical purposes differs from many other clinical genetic tests in several ways. First, the long-term stability of DNA may permit questions to be answered later that were not envisioned at the time of its procurement. Second, since DNA analyses commonly involve linkage analysis, a concept that is unfamiliar to laypersons and to many health care professionals, there is a significant risk of misinterpretation of results by recipients. Third, the rapid advance of DNA diagnostic capabilities places special responsibilities on the providers of these services to keep current.

DNA fingerprinting is a powerful new tool for law enforcement officials and is regarded as the most important breakthrough in forensic science. The new technology is used to identify and prosecute violent criminals as well as to exonerate innocent persons who are suspects in criminal cases. One of the major advantages of 'DNA fingerprinting' is that at present police can remove samples of DNA from individuals suspected for a specific crime, commonly by the removal of cells from the mouth using a cheek swab, or from minute samples of blood,

kin cells, semen or even a single hair. The condition or age of these biological samples does not affect the ability of the method to produce DNA fingerprints. The DNA thus obtained from the suspect can then be compared to any genetic material found at the scene of the crime. The DNA database creation thus might be helpful for the investigators to use DNA in order to search for a suspect, rather than merely to provide evidence once the suspect has been apprehended. However, it would be possible to require that the database contain only the DNA fingerprint of persons arrested or even only the profiles of convicted criminals.

There are several advantages of DNA fingerprinting over conventional means of forensic crime detection. Conventional fingerprints attach only to hard surfaces, can be smeared, can be wiped off, or avoided by the use of gloves and most of the time even a clear print requires a significant degree of interpretation by investigating officers which may result in severe criticism in some cases. The novel 'polymerase chain reaction' (PCR) amplification technique facilitates an accurate DNA profile from very small amounts of genetic data and these kinds of fingerprinting can be constructed notwithstanding substances such as contamination from oil, water or acid in the crime scene environment. The innocent and the accused should appreciate a novel fingerprinting technique that is both objective and accurate. The DNA will only be utilized in the detection of crime. In short, the innocent citizen should have nothing to fear. The invasiveness of the database resides in the information being maintained on file, rather than in the procedure for obtaining the genetic data.

The creation of a DNA database would not necessarily require a huge investment of time or public resources. The requisite computer and laboratory technology is already available in Bangladesh. Like many western countries, the law enforcing agencies may plan to require all convicted criminals to provide blood and saliva samples for DNA fingerprinting. The United States has developed the Combined DNA Index System (CODIS). Such an index system can eventually be developed in the country The expense of sampling the required suspected population would not be substantially high compared to the grave consequences of the committed crimes.

Everyday news papers are bringing out the incidence of overall levels of crimes in the country and it is increasing. Thus, there is an urgent need to create DNA banking and DNA database if we want to address the issue effectively. The idea of DNA banking information for future criminal investigations is not new anymore. If DNA profiles of samples from a population were stored in computer databanks (databases), DNA typing could be applied in crimes without suspects. Investigators could compare DNA profiles of biological evidence samples with a databank to search for suspects. DNA detection will be best equipped to identify the guilty. A full database should allow the use of DNA as an investigative tool where no suspect has yet been identified.

The increased use of DNA evidence will minimize the risk of future wrongful convictions. An FBI study indicates that since 1989 DNA evidence has excluded the primary candidate in 25 percent of sexual assault cases. Moreover, forensically valuable DNA can be found on evidence that has existed for decades, and thus assist in reversing previous miscarriages of justice. The database is immaterial to the acquittal or exclusion of non-offenders. Where a primary suspect has been identified, a DNA profile ought to be created and compared to the crime scene data. Likewise, where suspicions persist concerning the guilt or innocence of a convicted individual, a sample of DNA can be a guide in identifying a criminal from the existing database.

With the advanced Information Technology and the availability of expertise in Molecular Biology and Bioinformatics available within the country, it is high time for us to set up a DNA banking system with resources available for DNA fingerprinting to combat "terrorism" as well as to identify "criminals" in the society.

Prof. S A M Khairul Bashar, Ph.D is Pro-Vice Chancellor, North South University.