Forensic aspects of mass disasters: Strategic considerations for DNA-based human identification

Human blood identification using the genome profiling method

In criminal investigations, usually it is necessary to identify whether blood spots found at crime scenes are from humans or not. Nowadays, immunohistochemical methods and DNA analysis are usually used for this purpose. However, such methods and DNA analysis are labor intensive and expensive, and require highly trained skilled technicians. Recently, the genome profiling method (GP method) was developed. However, its use as a human DNA analysis method has not been reported. In this report, an attempt was made to differentiate human blood samples from animal blood samples using the GP method for forensic purposes. DNA extracted from a rat, squirrel, cat, dog, cow, and antelope along with human blood samples were analyzed. Following cluster analysis the human samples clustered into a single group separate from the animal samples. Therefore, although the number of samples was small the results suggest that the GP method might enable us to differentiate human samples from various animal samples. It may become a powerful tool in the field of forensic science.

Mesiodistal width of canines: a tool for sex determination

Teeth, in the living as well as the dead, are the most useful objects in the field of forensic investigation. Their ability to survive in situations like mass disasters makes them important tools in victim identification. Though the morphology and structure is similar in both men and women, there are subtle differences. Variation in dental size can give a clue about differences between the sexes. Many authors have measured the crowns of teeth in both men and women and found certain variations. Canines, reported to survive air crash and hurricane disasters, are perhaps the most stable teeth in the oral cavity because of the labiolingual thickness of the crown and the root anchorage in the alveolar process of the jaws. Measurement of mesiodistal width of the mandibular and maxillary canines provides good evidence of sex identification due to dimorphism.

Gender variation in morphological patterns of lip prints among some north Indian populations

BACKGROUND

Personal identification is an integral part of forensic investigations. For the same, DNA profiling and fingerprints are the most commonly used tools. But these evidences are not ubiquitous and may not necessarily be obtained from the crime scene. In such a scenario, other physical and trace evidences play a pivotal role and subsequently the branches employed are forensic osteology, odontology, biometrics, etc. A relatively recent field in the branch of forensic odontology is cheiloscopy or the study of lip prints. A comparison of lip prints from the crime scene and those obtained from the suspects may be useful in the identification or narrowing down the investigation.

AIM

The purpose of the present study is to determine the gender and population variability in the morphological patterns of lip prints among brahmins, Jats, and scheduled castes of Delhi and Haryana, India.

SETTINGS AND DESIGN

Samples were collected from Jats, brahmins, and scheduled castes of Delhi and Haryana. The total sample size consisted of 1399 individuals including 781 males and 618 females in the age group of 8-60 years. Care was taken not to collect samples from genetically related individuals. The technique was standardized by recording lip prints of 20 persons and analyzing them.

MATERIALS AND METHODS

Lip prints were collected by using a corporate's invisible tape and analyzed using a hand lens. The patterns were studied along the entire length and breadth of both the upper and the lower lip. The data were analyzed by SPSS statistical package version 17 to determine the frequencies and percentages of occurrence of the pattern types in each population group and a comparison between males and females among the groups was carried out by using the z test.

RESULTS AND CONCLUSIONS

The z-test comparison between patterns of males and females shows significant differences with respect to pattern types I', II, III, and IV among brahmins; I', II, III, IV, and Y among Jats; and I, I', II, III, and V among scheduled castes. Thus, it can be concluded that the variability of the lip print pattern can help sex differentiation among groups and that more studies on the lip print pattern should be carried out to bring new dimensions to forensic anthropology and to aid the law enforcement agencies.

Integrating forensic anthropology into Disaster Victim Identification

This paper will provide mass fatality emergency planners, police, medical examiners, coroners and other Disaster Victim Identification (DVI) personnel ways to integrate forensic anthropologists into DVI operations and demonstrate how anthropological contributions have improved DVI projects. In mass disaster situations, anthropologists have traditionally been limited to developing biological profiles from skeletal remains. Over the past decade, however, anthropologists' involvement in DVI has extended well beyond this traditional role as they have taken on increasingly diverse tasks and responsibilities. Anthropological involvement in DVI operations is often dictated by an incident's specific characteristics, particularly events involving extensive fragmentation, commingling, or other forms of compromised remains. This paper will provide examples from recent DVI incidents to illustrate the operational utility of anthropologists in the DVI context. The points where it is most beneficial to integrate anthropologists into the DVI process include: (1) during recovery at the disaster scene; (2) at the triage station as remains are brought into the mortuary; and (3) in conducting the reconciliation process. Particular attention will be paid to quality control and quality assurance measures anthropologists have developed and implemented for DVI projects. Overall, this paper will explain how anthropological expertise can be used to increase accuracy in DVI while reducing the project's cost and duration.

Comparison of three methods of DNA extraction from human bones with different degrees of degradation

There is a necessity for deceased identification as a result of many accidents and sometimes bones are the only accessible source of DNA. So far, a universal method that allows for extraction of DNA from materials at different stages of degradation does not exist. The aims of this study were: the comparison of three methods of DNA extraction from bones with different degree of degradation and an evaluation of the usefulness of these methods in forensic genetics. The efficiency of DNA extraction, the degree of extract contamination by polymerase chain reaction (PCR) inhibitors and the possibility of determining the STR loci profile were especially being compared. Nuclear DNA from bones at different states of degradation was isolated using three methods: classical, organic phenol–chloroform extraction, DNA extraction from crystal aggregates and extraction by total demineralisation. Total demineralisation is the best method for most cases of DNA extraction from bones, although it does not provide pure DNA. DNA extraction from aggregates removes inhibitors much better and is also a good method of choice when identity determination of exhumed remains is necessary. In the case of not buried bones (remains found outside) total demineralisation or phenol–chloroform protocols are more efficient for successful DNA extraction.

Use of prior odds for missing persons identifications

Identification of missing persons from mass disasters is based on evaluation of a number of variables and observations regarding the combination of features derived from these variables. DNA typing now is playing a more prominent role in the identification of human remains, and particularly so for highly decomposed and fragmented remains. The strength of genetic associations, by either direct or kinship analyses, is often quantified by calculating a likelihood ratio. The likelihood ratio can be multiplied by prior odds based on nongenetic evidence to calculate the posterior odds, that is, by applying Bayes' Theorem, to arrive at a probability of identity. For the identification of human remains, the path creating the set and intersection of variables that contribute to the prior odds needs to be appreciated and well defined. Other than considering the total number of missing persons, the forensic DNA community has been silent on specifying the elements of prior odds computations. The variables include the number of missing individuals, eyewitness accounts, anthropological features, demographics and other identifying characteristics. The assumptions, supporting data and reasoning that are used to establish a prior probability that will be combined with the genetic data need to be considered and justified. Otherwise, data may be unintentionally or intentionally manipulated to achieve a probability of identity that cannot be supported and can thus misrepresent the uncertainty with associations. The forensic DNA community needs to develop guidelines for objectively computing prior odds.

Multiplex genotyping system for efficient inference of matrilineal genetic ancestry with continental resolution

Background

In recent years, phylogeographic studies have produced detailed knowledge on the worldwide distribution of mitochondrial DNA (mtDNA) variants, linking specific clades of the mtDNA phylogeny with certain geographic areas. However, a multiplex genotyping system for the detection of the mtDNA haplogroups of major continental distribution that would be desirable for efficient DNA-based bio-geographic ancestry testing in various applications is still missing.

Results

Three multiplex genotyping assays, based on single-base primer extension technology, were developed targeting a total of 36 coding-region mtDNA variants that together differentiate 43 matrilineal haplo-/paragroups. These include the major diagnostic haplogroups for Africa, Western Eurasia, Eastern Eurasia and Native America. The assays show high sensitivity with respect to the amount of template DNA: successful amplification could still be obtained when using as little as 4 pg of genomic DNA and the technology is suitable for medium-throughput analyses.

Conclusions

We introduce an efficient and sensitive multiplex genotyping system for bio-geographic ancestry inference from mtDNA that provides resolution on the continental level. The method can be applied in forensics, to aid tracing unknown suspects, as well as in population studies, genealogy and personal ancestry testing. For more complete inferences of overall bio-geographic ancestry from DNA, the mtDNA system provided here can be combined with multiplex systems for suitable autosomal and, in the case of males, Y-chromosomal ancestry-sensitive DNA markers.

Past, present and future of forensic DNA typing

Recent advances in our ability to dissect the human genome and the availability of platforms for genome-wide analysis and whole-genome sequencing are expected to develop new tools for both biomedical and forensic DNA analyses. Nowadays, we can individualize single cells left at the crime scene or analyze ancient human remains. Here, we provide a general view on the past, current and likely future directions of forensic DNA analysis.

The strategies to DVI challenges in Typhoon Morakot

Small village populations in which there is a high amount of kinship can cause complications in cases of disaster victim identification. This problem was highlighted by the loss of life after Typhoon Morakot struck Taiwan where over 500 people from small isolated communities lost their lives. Most of the victims were buried by landslides in the remote mountainous areas of southern Taiwan. Only 146 pieces of human remains were recovered after searching for 4 months. Most of the human remains were received for examination as severely damaged fragments prevented possible identification by morphological features. DNA testing using the traditional duo parent/child or sibling screening by STR data opens the possibility of including not only the actual victim but also false positives. Variable likelihood ratios were obtained when comparing DNA types from human remains to those from potential relatives; however, with the DNA typing of numerous members of the same living family, multiple matches to potential families were avoided. Of the 146 samples obtained and collapsed to 130 victims, they were linked to 124 individuals resulting in their identification when compared to a pool of 588 potential relatives. Six of the human remains could not be linked to any living relative and remain unknown.

Y-STR variation in Albanian populations: implications on the match probabilities and the genetic legacy of the minority claiming an Egyptian descent

Y chromosome variation at 12 STR (the Powerplex® Y system core set) and 18 binary markers was investigated in two major (the Ghegs and the Tosks) and two minor (the Gabels and the Jevgs) populations from Albania (Southern Balkans). The large proportion of haplotypes shared within and between groups makes the Powerplex 12-locus set inadequate to ensure a suitable power of discrimination for the forensic practice. At least 85% of Y lineages in the Jevgs, the cultural minority claiming an Egyptian descent, turned out to be of either Roma or Balkan ancestry. They also showed unequivocal signs of a common genetic history with the Gabels, the other Albanian minority practising social and cultural Roma traditions.

A new set of markers for human identification based on 32 polymorphic Alu insertions

A number of genetic systems for human genetic identification based on short tandem repeats or single nucleotide polymorphisms are widely used for crime detection, kinship studies and in analysis of victims of mass disasters. Here, we have developed a new set of 32 molecular genetic markers for human genetic identification based on polymorphic retroelement insertions. Allele frequencies were determined in a group of 90 unrelated individuals from four genetically distant populations of the Russian Federation. The mean match probability and probability of paternal exclusion, calculated based on population data, were 5.53 x 10(-14) and 99.784%, respectively. The developed system is cheap and easy to use as compared to all previously published methods. The application of fluorescence-based methods for allele discrimination allows to use the human genetic identification set in automatic and high-throughput formats.

Whole genome amplification and real-time PCR in forensic casework

Background

WGA (Whole Genome Amplification) in forensic genetics can eliminate the technical limitations arising from low amounts of genomic DNA (gDNA). However, it has not been used to date because any amplification bias generated may complicate the interpretation of results. Our aim in this paper was to assess the applicability of MDA to forensic SNP genotyping by performing a comparative analysis of genomic and amplified DNA samples. A 26-SNPs TaqMan panel specifically designed for low copy number (LCN) and/or severely degraded genomic DNA was typed on 100 genomic as well as amplified DNA samples.

Results

Aliquots containing 1, 0.1 and 0.01 ng each of 100 DNA samples were typed for a 26-SNPs panel. Similar aliquots of the same DNA samples underwent multiple displacement amplification (MDA) before being typed for the same panel. Genomic DNA samples showed 0% PCR failure rate for all three dilutions, whilst the PCR failure rate of the amplified DNA samples was 0% for the 1 ng and 0.1 ng dilutions and 0.077% for the 0.01 ng dilution. The genotyping results of both the amplified and genomic DNA samples were also compared with reference genotypes of the same samples obtained by direct sequencing. The genomic DNA samples showed genotype concordance rates of 100% for all three dilutions while the concordance rates of the amplified DNA samples were 100% for the 1 ng and 0.1 ng dilutions and 99.923% for the 0.01 ng dilution. Moreover, ten artificially-degraded DNA samples, which gave no results when analyzed by current forensic methods, were also amplified by MDA and genotyped with 100% concordance.

Conclusion

We investigated the suitability of MDA material for forensic SNP typing. Comparative analysis of amplified and genomic DNA samples showed that a large number of SNPs could be accurately typed starting from just 0.01 ng of template. We found that the MDA genotyping call and accuracy rates were only slightly lower than those for genomic DNA. Indeed, when 10 pg of input DNA was used in MDA, we obtained 99.923% concordance, indicating a genotyping error rate of 1/1299 (7.7 × 10^-4). This is quite similar to the genotyping error rate of STRs used in current forensic analysis. Such efficiency and accuracy of SNP typing of amplified DNA suggest that MDA can also generate large amounts of genome-equivalent DNA from a minimal amount of input DNA. These results show for the first time that MDA material is suitable for SNP-based forensic protocols and in general when samples fail to give interpretable STR results.

Development of a spreadsheet for SNPs typing using Microsoft EXCEL

Single-nucleotide polymorphisms (SNPs) have some characteristics that make them very appropriate for forensic studies and applications. In our institute, SNPs typings were performed by the TaqMan SNP Genotyping Assays using the ABI PRISM 7500 FAST Real-Time PCR System (AppliedBiosystems) and Sequence Detection Software ver.1.4 (AppliedBiosystem). The TaqMan method was desired two positive control (Allele1 and 2) and one negative control to analyze each SNP locus. Therefore, it can be analyzed up to 24 loci of a person on a 96-well-plate at the same time. If SNPs analysis is expected to apply to biometrics authentication, 48 and over loci are required to identify a person. In this study, we designed a spreadsheet package using Microsoft EXCEL, and population data were used from our 120 SNPs population studies. On the spreadsheet, we defined SNP types using 'template files' instead of positive and negative controls. "Template files" consisted of the results of 94 unknown samples and two negative controls of each of 120 SNPs loci we had previously studied. By the use of the files, the spreadsheet could analyze 96 SNPs on a 96-wells-plate simultaneously.

Enhancing accurate data collection in mass fatality kinship identifications: lessons learned from Hurricane Katrina

A mass fatality DNA identification effort is a complex process in which direct matching and kinship analysis is used for identifying human remains. Kinship DNA identification is an important tool in the identification process in which victim's DNA profiles are compared to the profiles of "known" biologically related reference samples. Experience from the 9/11 World Trade Center DNA identification efforts showed that forms used to record biological relationships are important and that inaccurately documented information may hamper the kinship analysis and DNA identification process. In the identification efforts following Hurricane Katrina, a Family and/or Donor Reference Collection (FDRC) form was used as a means to document the reported relationship between the reference DNA donor and the purported missing individual. This FDRC form was developed based upon lessons learned from 9/11 and the Tsunami identification efforts. This paper analyses the effectiveness of the FDRC form used in the Hurricane Katrina kinship DNA identification efforts and proposes an improved sample collection form for kinship and other donor reference samples. The data presented can be used to enhance the accuracy of the data collection process through an improved sample collection form, streamlining the DNA kinship identification process and decreasing the burden on valuable resources.

DNA analysis in perpetrator identification of terrorism-related disaster: suicide bombing of the Australian Embassy in Jakarta 2004

We report the strategy that we employed to identify the perpetrator of a suicide car bombing in front of the Australian Embassy in Jakarta, Indonesia, on 9 September 2004. The bomb was so massive that only small tissue pieces of the perpetrator could be recovered, preventing conventional approach to the identification of the bomber, necessitating the introduction of DNA analysis as the primary means for perpetrator identification. Crime scene investigation revealed the trajectory of the bomb blast, which was used to guide the collection of charred tissue fragments of the perpetrator. Mitochondrial DNA analysis was first conducted on 17 tissue fragments, recovered over large areas of the trajectory to, (a) confirm that they are of a common source, i.e. the perpetrator, and thus (b) establish the mtDNA HV1 sequence profile of the perpetrator. The mtDNA of the perpetrator matches that of a maternally related family member of one of four suspects. Standard autosomal STR analysis confirmed the identification. This case is of interest as an illustration of a successful application of DNA analysis as the primary means of disaster perpetrator identification.

First successful assay of Y-SNP typing by SNaPshot minisequencing on ancient DNA

In the present study, a set of 13 Y-chromosomal single nucleotide polymorphisms (Y-SNPs) selected for the identification of the most frequent Asian Y-haplogroups was included in an allele-specific primer extension assay. Single nucleotide polymorphism (SNP) genotyping was accomplished by co-amplification of these 13 DNA fragments within 2 multiplex PCRs followed by detection with 1 minisequencing reaction using the SNaPshottrade mark Multiplex kit and analysis of extension products by capillary electrophoresis. First developed on modern samples, the assay was optimized for the analysis of 11 ancient DNA (aDNA) samples from the Krasnoyarsk region (southern Siberia) that were dated from 5,500-1,800 years before present (YBP). SNP typing was successful for most of them, which were all assigned to Y-haplogroup R1a1 except one. These results show that SNPs are well-suited for the analysis of aged and degraded DNA samples. Moreover, we found that the SNaPshot minisequencing methodology is a convenient, robust, and efficient method for SNP typing. To our knowledge, this study reports the first successful investigation of Y-SNPs on aDNA samples. The potential use of Y-SNPs in both evolutionary and forensic fields is also discussed.

DNA Commission of the International Society for Forensic Genetics (ISFG): recommendations regarding the role of forensic genetics for disaster victim identification (DVI)

The ISFG membership consists of scientists and medical professionals specialized in using genetic testing for kinship analysis and the individualization of biological material. This expertise makes the forensic geneticist a resource of advice to international and national organizations dealing with human identifications and causes many DNA laboratories to get involved in DVI tasks. The present recommendations are meant to educate more forensic geneticists about their potential involvement in mass fatality preparedness and possible DVI efforts, as well as to provide practical guidance for each of the laboratories' individual tasks. The idea to work on DNA-specific recommendations was born after a round table discussion dealing with the 2004 Tsunami disaster in south east Asia during the 21st congress of the International Society for Forensic Genetics on the Azores, Portugal, in September 2005. The ensuing discussion between scientists and pathologists that had been involved in the International Center in Khao Lak, Thailand, revealed the need for the scientific community to be better prepared to answer the local authorities' questions by formulating generally acceptable scientific standards for the most efficient use of DNA-based victim identification methods. These recommendations, as well as the many cited references, are intended to provide guidance on establishing preparedness for the forensic genetics laboratory, on collecting and storing ante-mortem and post-mortem samples suitable for DNA analysis, on DNA extraction and genetic typing strategies, on data management, and on issues related to the biostatistical interpretation and reporting of results.

DNA Fingerprinting in the Criminal Justice System: An Overview

DNA fingerprinting is a powerful technology that has revolutionized forensic science. No two individuals can have an identical DNA pattern except identical twins. Such DNA-based technologies have enormous social implications and can help in the fight against crime. This technology has experienced many changes over time with many advancements occurring. DNA testing is a matter of serious concern as it involves ethical issues. This article describes various trends in DNA fingerprinting and the current technology used in DNA profiling, possible uses and misuses of DNA databanks and ethical issues involved in DNA testing. Limitations and problems prevailing in this field are highlighted.

Turning base hits into earned runs: improving the effectiveness of forensic DNA data bank programs

Forensic data banks contain biological samples and DNA extracts as well as computerized databases of coded DNA profiles of convicted offenders, arrestees and crime scene samples. When used for investigative and law enforcement purposes, DNA data banks have been successful in providing key investigative leads in hundreds of criminal investigations. A number of these crimes would never have been resolved without use of such data banks. In addition, in some limited number of investigations, the exclusion of known suspects whose DNA profiles are known to be in an offender database can save valuable investigative time.

Despite the above benefits, in hundreds of cases DNA samples are never collected and administrative and laboratory logjams delay prompt database searches. Furthermore, hundreds of DNA database matches (hits) languish, without any followup by law enforcement or prosecutors. These prevent or delay DNA matches and therefore can leave the public in grave risk of potential harm from recidivistic offenders who otherwise could have been apprehended and convicted if the process functioned more effectively.

EPIDEMIOLOGY: Enhanced: DNA Identifications After the 9/11 World Trade Center Attack

The attack on the World Trade Center on 9/11/2001 challenged current approaches to forensic DNA typing methods. The large number of victims and the extreme thermal and physical conditions of the site necessitated special approaches to the DNA-based identification. Because of these and many additional challenges, new procedures were created or modified from routine forensic protocols. This effort facilitated the identification of 1594 of the 2749 victims. In this Policy Forum, the authors, who were were members of the World Trade Center Kinship and Data Analysis Panel, review the lessons of the attack response from the perspective of DNA forensic identification and suggest policies and procedures for future mass disasters or large-scale terrorist attacks.