For decades, many dead bodies or remnants of body parts have lingered in the back rooms of morgues. In 1949, the famous “Acid Bath Murderer” which is the name of the cunt John George Haigh had killed his last victim and drowned the victim’s body in one of the most gruesome way to completely disappear the remains, via the actions of Sulphuric Acid. He murdered at least 6 people and was actually caught when he arrogantly lead the police to the remains of the final victim. He proudly thinks that those cops couldn’t actually figure out what happened, as he implies “the perfect murder”. Olivia Durand-Deacon, a 69 year old widow of a solicitor whom lives in London was the last victim of this demonic murderer.
The police has found a carboy (a container used to hold acid), a steel drum, a pump and a revolver in Haigh’s workshop. With arrogance, he said that “I have destroyed her in acid. You will find sludge that remains at Leopold Road. Every trace has gone. How can you prove murder if there is no body?" During the next day, a pathologist from Scotland Yard searched his workshop to find more evidence pertaining to the case. Simpson, the pathologist, managed to identify “finely splattered blood stains” on one of the workshop’s wall and puddles of “yellowish white” sludge nearby the building.
The crime was unveiled by the pathologist when they managed to dug out some of Olivia’s remains nearby the sludge. 28 pounds of human body fat, a partial left foot, 18 human bone fragments from spinal and heel columns, three human gallstones, a complete set of dentures, and a handle of a red purse were all found. Eerie isn't it? The deceased dental surgeon examined the false teeth and confirmed that those are Olivia’s as they fit perfectly with the dental records. Haigh was charged of Durand-Deacon’s murder on March 1949. The crime has occurred many years before the sophisticated DNA analysis was possible. Thanks to the amazingly diligent forensics analyst work to unveil the notorious Haigh’s crime, we are still able to figure out nasty motives of any murderers even without DNA analysis.
Ever since DeoxyriboNucleicAcid (DNA) particle was isolated by the genius Friedrich Miescher in the 17th century, many clinical and forensics research were done to further exploit the usage of this DNA. Another notable person in this field is the brilliant American Biochemist Kary Banks Mulllis. She managed to improve Polymerase Chain Reaction (PCR) for boosting DNA sequencing, which led to many further innovation in this field. In the 21st century, right now, the medical field has used PCR in many occasions such as in disease identification and paternity tests. The law enforcement department has reap some benefits from this invention too. So now, I’m going to explain about how does DNA Analysis is being done.
There are several basic steps in DNA Analysis which are the common steps regardless of any type of DNA testing.
Steps:
- DNA isolation from its origin
- The DNA processing
- The result interpretation
- The comparison of the test results from the unknown and known samples to determine whether the known individual is not the source of DNA or is included as one of the possible sources of DNA
Steps in DNA processing:
• Biology – Following the collection of samples, the DNA is extracted from its biological source material and the DNA quantity is measured. PCR is done afterwards. PCR amplifies the number of DNA content up to millions of copies for each DNA segment of interest. Multiple Short Tandem Repeats regions can be examined together to boost the yield of the result.
• Technology – The resulting product from PCR are separated via slab gel and capillary electrophoresis (EP). After determining the STR alleles, a process known as the sample genotyping is done. The specific methods in each laboratory is continuously updated to the current available technology for better outcomes.
• Genetics – With paternity investigation, the samples were compared with the reference sample (ie, the alleged father of the victim). If there is no match between the questioned sample and the known sample, the samples may have been originated from different sources. Finally, a report is generated based on the outcome of the DNA analysis.
What are the types of DNA evidence analysis?
Medical students in the National University of Malaysia are compulsory to enroll him/herself in a special module, namely the Special Study Module or SSM. This module divides us into small groups under supervisors of various departments such as Surgery, Parasitology, Emergency Medicine, and Ophthalmology. It’s no surprise to you guys that I’ve selected to be under the Forensics Department and that’s the main reason why I am writing this article. DNA analysis is the key to forensics investigation as the result is very precise. There are several types of DNA analysis methods including the PCR, STR Analysis, Y-Chromosome Analysis and Mitochondrial Analysis.
Polymerase Chain Reaction
The brilliant American Biochemist, Dr Kary Mullis became a star when she discovered that DNA could be copied in the lab, which I have mentioned earlier. The copying process, uses the enzyme Polymerase to replicate the DNA regions in a test tube. I have discussed about protein synthesis which includes the DNA transcribing process in my first pharmacology post which was about Anti-Virals. My adding this magical enzyme, a small number of DNA can further multiply to an astounding billions of DNAs within several hours. Since PCR amplifies all the DNA that is inside the sample, it might also replicate contaminations thus proper collection and storage of the DNA sample is highly appreciated.
Short Tandem Repeat (STR) Analysis
STR analysis involves the evaluation of specific regions or loci that are found in the DNA. The variable or polymorphic nature of the STR regions that are analyzed for forensics testing amplifies the discrimination between one's DNA profile and another. Confusing eh? Alright. For example, the likelihood of any two individuals will have the same 13-region DNA profile can be as high as 1 in 1 billion, or probably much greater. Hence, it is quite specific. The famous FBI, which is a shortform of Federal Bureau of Investigation has selected 13 specific STR loci as the standard of CODIS (Combined DNA Index System). CODIS is the FBI’s program of support for criminal justice DNA databases.
More details of STR analysis can be read here:
• https://www.fbi.gov/services/laboratory/biometric-analysis/codis/codis-and-ndis-fact-sheet
• https://nij.gov/training/pages/training-detail.aspx?itemid=78
• http://strbase.nist.gov/
DNA Typing – Y-Chromosome Analysis
Y-chromosome only targets the male fraction of a sample as male’s chromosomes are made up of X and Y instead of just X in females. Hence, this technique is important if the lab manages to detect multiple male contributors in the sample. It can be done even in paternity testing especially among males. Further advancements in this testing eventually will eliminate the need to vaginal and semen samples separation before the analysis process. This is especially true in cases of vaginal swab of a rape kit.
DNA Typing – Mitochondrial Analysis
The other name of it is mtDNA is slightly different from PCR. PCR amplifies DNA but mtDNA technology analyzes the mitochondrion in different parts of the cells. PCR requires the nucleus as the DNA is stored in the nucleus. In mtDNA analysis, samples that lack of nucleus such as hair shafts, bones and teeth, may yield results if this type of DNA analysis is used. For this particular reason, mtDNA is valuable to investigate unsolvable cases. The other example is when the sample is not analyzed in a long period of time. DNA degradation can happen over time as in vaginal or semen samples and this will result in PCR-negative outcome. However, hair shafts or teeth could be sent for mtDNA analysis and the outcome might differ from the PCR’s. Lastly, it is essential to take note that all the maternal relatives have identical mtDNA. Hence that’s why mitochondrial diseases are inherited by only the female lines. This process enables the unidentified remains to be analyzed and compared with the female relatives.
Further readings in mtDNA
• https://nij.gov/topics/forensics/evidence/dna/research/pages/mitochondrial.aspx
So we have seen all the great benefits that DNA analysis has brought to the forensics field. What are the cons?
Familial relationship often present with complex affairs that can’t be solved by genetic testing. Divorce cases, child out of wedlock, adopted children are all the examples to this. Forensics use of DNA analysis is never free from contamination, irresponsible handling of the samples, unskilled technicians, and the lacking of available facilities. Imagine if there’s a plane crash that involved over 300 victims, are you going to test each and every one of them via DNA analysis?
There are three other ways that forensics analyst can determine the unidentified dead bodies, namely the Dental X-Rays and Dentures, Surgical Implants, and the Skeletal diseases of the long and short bones.
• Dental X-Rays/Dentures – this method is considered as one of the best ways to identify the deceased. Many features in the mouth are unique to an individual like the Olivia’s case which I’ve mentioned in the opening of this article. The sulphuric acid did not manage to harm the dentures. The features are the tooth root curvature, tooth position, impacted teeth, extra teeth and tooth crown anomalies. The dental X-rays of the dead person is taken and compared with the old dental records.
• Surgical Implants are indestructible by most calamities. They are mostly constructed of durable materials such as Titanium. “You shoot me down, but I won’t fall, I am Titanium”. Sia is right after all. Moreover, surgical devices are usually located deep in the body which provides them with additional protection.
• The long and short bones – The evidence of previous injury such as bone fractures can identify after death if antemortem x-rays are available. Diseases such as Extra-pulmonary Tuberculosis, Syphilis, and Psoriasis can cause skeletal damage and it would be unique to some individuals. Hence, it is essential to trace the old medical records.
In brief, DNA analysis is the most supreme method for corpse identification and our technology advancements such as PCR, STR, Y-Chromosomes and mtDNA are very valuable in assisting these dreadful cases. Olivia’s case is quite a horrendous one isn’t it?
Body identification via DNA requires an ample amount of cash, many dilligent forensics analysts, and adequate facilities in cases of mass disasters, murders and accidents those involving many dismembered body parts. Hence, extensive research should be done in order to find other methods for victim identification especially in developing countries in which massive DNA analysis do not fit in well. That’s all for today’s post. Thanks for reading and have a pleasant day :)
References
- Learn About the Pros and Cons of DNA testing. The Law Dictionary. Retrieved on April 15, 2018, from https://thelawdictionary.org/article/learn-about-the-pros-and-cons-of-dna-testing/
- 3 Ways to Identify a Body when DNA is not an option. Forensics Outreach. Retrieved on April 15, 2018, from http://forensicoutreach.com/library/three-ways-to-identify-a-body-when-dna-is-not-an-option/
- Cold Case Chronicles: The Acid Bath Murders. Forensicsmag. Retrieved on April 15, 2018, from https://www.forensicmag.com/article/2017/03/cold-case-chronicles-acid-bath-murders
- How Identifying A Body In Real Life Is Nothing Like TV or Movies. Retrieved on April 15, 2018, from https://www.forensicmag.com/article/2017/03/cold-case-chronicles-acid-bath-murders