DNA profiling for crime investigation
Abstract— DNA profiling also called as DNA typing or Gene fingerprinting has been used as a powerful process for identification of humans. Many countries around the world where forensic databases have created to store DNA patterns(DNA profiles) of crime scenes in order to put the actual criminals behind the bars and free the innocent who have been kept in jails for years without any real evidence of crime.
DNA profiling is not just limited in crime investigations but have got many other applications as to detect paternity child case investigation, Huge mass detection in big disasters, to detect severe diseases beforehand like cancer, diabetes etc. In Forensic Science, manual investigation has to be automated in a way to store more and more DNA profiles in database so that crime rate reduces at higher pace. Keywords— DNA, DNA Profiling, Forensic Science, CODIS, DNA Testing I.
Deoxyribonucleic Acid (DNA) sequencing is well established process that is used to identify individuals especially in forensic DNA analysis that involves crime investigation. At first glance question arises in mind why just a DNA sequence is considered for crime investigation process though there are other software present that can identify a criminal like Fingerprint Recognition Systems, Iris Recognition Systems, Palm Recognition Systems, Retina recognition systems, Thumb recognition systems and others.
Actually what happens is when crime scene happened the criminals are very sharp because they do know the investigations will get started and it’s not so simple to run away from crime scene? So they tried not to leave any kind of fingerprints. At this time DNA profiling plays a vital role to investigate these situations and get precise and accurate results in the form of perfect match of DNA sample. Genetic tests have been widely used for forensic evidences and mass- fatality identification (terrorist attacks, airplane crash, and tsunami disaster.
Genetic testing results are integrated with information collected by multidisciplinary teams composed of medical examiners, forensic pathologists, anthropologists, forensic dentists, fingerprint specialists, radiologists and experts in search and recovery of physical evidence. Large scale tissue sampling and long-term DNA preservation under desiccation conditions with potential applications in mass fatalities has been recently described [2-4]. In this paper, we present an overview of current research in Forensic Science. Section II states the problem statement.
Section III outlines the brief literature review on DNA, DNA Testing, Profiling and DNA Typing. Section IV describes the methodology of DNA Profiling, CODIS System. In Section V, we conclude with a summary of current problems in DNA Profiling in terms of cost and. time effectiveness. II. PROBLEM DEFINITION Considering DNA Profiling for crime investigation, instead of other biometrics like fingerprints Using cost effective and efficient system so that the real criminals can be traced out. III. Literature Review DNA is a molecule of life and main property of DNA is that is unique and found in all living organisms including virus.
DNA is a double helix structure means containing two strands with four bases named as Adenine, Cytosine, Thymine and Guanine which are held together with the help of bonds. These base pairs are connected to ribose and phosphate molecule. User can have a better view of this DNA double helix from the figure given below. Figure Structure of DNA molecule As DNA is unique for each individual and it contains millions of nucleotide base pairs (Adenine, Thymine, Cytosine, and Guanine). An individual DNA is made up of half of the DNA from father and half from mother so DNA testing process is used to know the evidence of paternity of children.
DNA is located in most of the human body parts like blood, saliva, hair roots, white blood cells and body tissues which can be DNA profiled. In this way genetic information is taken from the samples during crime scenes and then investigated for the evidence of the criminal. A. What is DNA DNA stands for Deoxyribonucleic Acid is a hereditary material which is found in all living organisms including virus. It is located in the cells within nucleus that contains genetic information in which many hidden secrets are waiting to be explored.
DNA contains 3 billion base pairs Adenine (A), Thymine (T), Cytosine(C) and Guanine (G) which are held together by strong hydrogen and covalent bonds. It is a ladder like structure vertical bars seems like pillars are made up of ribose and phosphate ions. The rungs of the ladder are composed of nucleotide base pairs which is actually needed to be stored as encrypted code in the database to process and identify people who are involved in crime or escape the innocent who have been in jail for years without committing any crime but after their DNA typing is being done will proved them for 100% accuracy that are not the suspects of crimes.
B. Forensic DNA Procedures Personal identification is conducted using special biological features like DNA, saliva, blood, etc. ), physiological features like fingerprints, eye irises and retinas, hand palm and facial features), behavioural characteristics including lip motion, dynamic signature. DNA plays a vital role in identification of individuals in which genetic patterns of inheritance are used as markers for unique identity of individuals. All humans have >99% same DNA sequences and still they have got millions of genetic differences. C.
What is DNA Profiling DNA profiling, otherwise known as DNA testing or genetic fingerprinting, is the process of identifying an individual from their unique sequence of loci (part of the chromosome), gained by accessing a sample of the individual’s DNA . Profiling is used by forensic scientists to find the identity of those involved in criminal activity. DNA Profiling which may also called as DNA typing or Genetic fingerprinting has been evolved as a revolutionary, powerful and reliable identification tool which has got lots of applications.
As far as other identification tools are also widely used for identification purpose like for example Finger Print Recognition System, Iris Recognition System, Palm Recognition System and Voice Recognition System etc. , all of these application softwares are implemented to solve real world problems especially for security purpose. DNA profiling is widely used in crime investigations, Paternity of child, Medical diagnosis and many others. DNA sequencing needed to increase the processing speed for sequencing the nucleotide base pairs.
DNA profiling is done by many techniques and still researchers are trying to invent cost effective and speedy techniques to process the DNA sequence in less time and give accurate result in the form of perfect match. These techniques like STR (Short Tandem Repeat profiling), Restriction Fragment Length Polymorphism (RFLP) and many others that involved the examination of successive regions of DNA. There is a population database that might be involved in crimes or might not be involved.
The distribution of DNA sequence which has been got from DNA profiling techniques are examined and will relate to the given DNA database to get the indication whether that DNA is related to the population sample present already in the database. D. DNA Typing 99. 9% of the DNA from two people will be identical. The 0. 1% of DNA code sequences that vary from person to person is what makes us unique . These sequences are called genetic markers, and are the part of the code that forensic scientists use when doing a DNA test .
It is a process of extraction of DNA fragments from reference sample found at the crime scene which is further analyzed and processed by many optimization techniques which will be discussed in later section. Then it will generate a genotype pattern in encrypted form that can be read and stored in computer system as National DNA Database. This unique pattern of DNA that is used for accurate identification of a person is called as DNA Profile which is unique for each individual with the exception of DNA profile that is derived from identical twins.
DNA Testing DNA is very powerful and efficient tool for identification and has got many other applications . Some of the uses are given below: 1) Parental Testing: It is used to know if someone is real father of a child or not. 2) Forensic testing: It is used crime investigation. 3) Gene therapy: It is used to establish birth defects and to test parents for genetic conditions. 4) Genetic genealogy: It is used to know more about someone’s ancestry. IV. Methodology A. Process Of DNA Profiling (Crime Investigation)
Take a reference sample of tissue found in crime scene, cut the DNA into fragments using biological techniques that might include RFLP(Reduced Fragment Length Polymorphism) after that do PCR(Polymerase Chain Reaction) analysis of DNA fragments which will create copies of DNA alleles or loci (specific location in chromosome) which represent Genotype data which will going to be converted to encrypted genetic code which computer , in case of crime investigation, analyst will use CODIS (Combined DNA Index System).
CODIS has incorporated two databases the one includes the genetic information of DNA sample which is a reference sample and other database included a population sample. CODIS will automatically process the sample DNA for the match if match found with population database then it will generate profile of the suspect accordingly. Figure Process of DNA Profiling V. Conclusion DNA profiling which is used in forensic evidences needed to be proficient in examining the suspect of crime.
The problem encountered in DNA profiling is the techniques which take much time to read the genetic code sequence. It takes exponential time to handle the DNA structure during testing and validation phase to ensure that the particular DNA belongs to right person or not. There should be a procedure to knock out this lengthy procedure and use some other technology that could be nanotechnology which is again a vast field to explore the things out to solve our real life problems.
What if system read the sequence directly from DNA instead of going through big lengthy complicated and time consuming procedures avoiding Petri Dish Testing of blood samples? Acknowledgment I would like to extend our heartiest gratitude to Dr. Maqbool Sheikh, for his invaluable guidance, inspirations and timely suggestions which facilitated the entire process of bringing out this research on “DNA Profiling for Crime Investigation”. It would have been really hard to complete this project successfully without the directions of Dr. Maqbool Sheikh.