Suspect Height Estimation Using the Faro Focus3D Laser Scanner

At present, very little research has been devoted to investigating the ability of laser scanning technology to accurately measure height from surveillance video. The goal of this study was to test the accuracy of one particular laser scanner to estimate suspect height from video footage. The known heights of 10 individuals were measured using an anthropometer. The individuals were then recorded on video walking along a predetermined path in a simulated crime scene environment both with and without headwear. The difference between the known heights and the estimated heights obtained from the laser scanner software were compared using a one-way t-test. The height estimates obtained from the software were not significantly different from the known heights whether individuals were wearing headwear (p = 0.186) or not (p = 0.707). Thus, laser scanning is one technique that could potentially be used by investigators to determine suspect height from video footage.     

Assessment of PowerPlex® Fusion 5C’s ability to type degraded DNA

DNA samples collected at crime scenes are often degraded so this research focused on the ability of the Promega PowerPlex® Fusion 5C amplification kit to type both naturally and artificially degraded DNA.DNA was degraded naturally by placing equal volumes of blood on white fabric that was stored either inside, outside in a shaded area, or outside in direct sunlight. Samples were then collected every 10 days for 60 days and the DNA extracted (QIAamp® DNA Investigator). Artificially degraded samples were created by exposing extracted DNA to either UV light or 95 °C heat for varying times. DNA was also degraded artificially by placing blood samples into a 50% bleach solution for varying times prior to extraction.Following sample treatment, standard forensic DNA analysis was performed including quantification (Investigator® Quantiplex) and amplification (PowerPlex® Fusion 5C). Separation and detection were performed on an ABI 3130xl capillary electrophoresis unit and analysis was performed using GeneMapper ID v3.2.1.While the time and shade samples showed similar amounts of degradation, the samples exposed to direct sun showed more degradation. The artificially degraded samples showed more signs of degradation such as reduced overall peak height and peak height imbalance at heterozygous loci. There were also some cases where an allele that was known to be in the profile exhibited total dropout. Although there were some instances of both allelic dropout and heterozygote peak imbalance, PowerPlex® Fusion was able to reliably type degraded DNA as all alleles detected were consistent with the known donor profile. The results show that PowerPlex® Fusion is a robust kit capable of handling forensically challenged samples.     

焦磷酸测序分析短片段牙釉质蛋白基因进行性别鉴定

目的采用焦磷酸测序技术分析短片段牙釉质蛋白基因进行性别鉴定并用于骨骼及腐败生物检材的检测。方法应用blast软件,确定牙釉质蛋白基因(Amel)上1段含有3个SNP位点及1个插入/缺失(indel)位点的序列作为待测靶序列,设计引物,扩增该段序列,应用焦磷酸测序技术分析扩增序列,进行性别鉴定。对方法进行准确性、灵敏度、种属特异性的测试,并用于对骨骼和高度降解DNA的检测。结果 PCR产物分别为44bp(Amel X)和45bp(Amel Y),女性测序结果为:G/G,T/T,…/…,C/C,男性测序结果为:G/T,T/A,…/C,C/A,分型图谱清晰。应用本文方法检测100份已知性别的DNA样本,结果均正确无误,方法最低DNA模板量为0.5ng,具有较好的人类种属特异性。用于高度降解DNA分析,较IdentifilerTM试剂盒具有更高的成功率且骨骼样本也得到清晰的分型结果。结论本文采用焦磷酸测序技术分析Amel的方法在法医学性别鉴定中有较好的应用价值。     

Simulation-based reconstruction of traffic incidents from moving vehicle mono-camera

Video recordings from digital cameras implemented in road vehicles present a valuable source of data concerning various dangerous traffic situations, i.e., road accidents or near-miss incidents. This data is readily available and numerous methods for forensic reconstruction of traffic situations from vehicle video were presented in the past. New alternative method for reconstruction of traffic situations from vehicle video is presented in this article. The method is based on the fusion of kinetic vehicle trajectory simulation within 3D laser scanner point cloud, projective geometry, and processing of video footage from moving vehicle camera. The method offers accurate reconstruction of general vehicle motion within relevant time domain whereby in-depth technical information about traffic incident can be quantitatively extracted from video footage. The result is physics-based 3D projection of simulated vehicle motion on the motion of real vehicle recorded by moving monocular camera. The method was validated within performed experimental test runs with respect to vehicle speed, distance travelled, acceleration/deceleration and directional quantities (yaw rate, yaw angle). The method was further applied in the reconstruction of real-world traffic events.     

Development of a forensic DNA phenotyping panel using massive parallel sequencing

The HIrisPlex-S system, targeting a total of 41 SNPs, allows the simultaneous eye, hair and skin color prediction from DNA. In the present study, we developed a massive parallel sequencing (MPS) multiplex assay in order to genotype all the HIrisPlex-S markers in degraded casework samples. PCR amplicons sizes of target regions were kept below 180 bp, in order to allow analysis of degraded DNA samples. Individuals with known phenotype, artificially degraded DNA samples and a set of 2800M control DNA dilutions were sequenced on a Ion PGM System, in order to evaluate the concordance testing results and the forensic suitability of this 41-plex MPS assay. Full and reliable profiles could be obtained with 0.1 ng of input DNA. The increment of the number of PCR cycles results in improvement of sensitivity or in typing results but an increase of artifacts were also observed.     

寡核苷酸芯片技术在HLA-A抗原基因分型中的应用研究

目的建立一种HLA-A位点的基因芯片分型方法,为HLA-A位点的基因分型提供一个较新的思路。方法利用基因芯片技术,根据HLA-A位点不同基因亚型的独特序列设计探针,制成分型芯片;待检测样品经PCR反应标记上荧光之后,与芯片进行杂交,根据杂交产生的荧光信号值分析确定样品HLA-A位点的基因亚型。将这一方法应用于100份标准DNA和200份无关个体的HLA-A位点基因分型并将部分样品进行测序。结果检测结果表明HLA-A基因分型芯片可准确分辨出A位点等位基因20大类,耗时2.5h。结论寡核苷酸芯片技术用于HLA-A基因分型,分辨率高、特异性强、重复性好、操作简便、结果直观,适合于法医学实践和临床应用。     

Using FastID to analyze complex SNP mixtures from indoor dust

Forensically relevant single nucleotide polymorphisms (SNPs) can provide valuable supplemental information to short tandem repeats (STRs) for investigative leads, and genotyping can now be streamlined using massively parallel sequencing (MPS). Dust is an attractive evidence source, as it accumulates on undisturbed surfaces, often is overlooked by perpetrators, and contains sufficient human DNA for analysis. To assess whether SNPs genotyped from indoor dust using MPS could be used to detect known household occupants, 13 households were recruited and provided buccal samples from each occupant and dust from five predefined indoor locations. Thermo Fisher Scientific Precision ID Identity and Ancestry Panels were utilized for SNP genotyping, and sequencing was completed using Illumina^® chemistry. FastID, a software developed to permit mixture analysis and identity searching, was used to assess whether known occupants could be detected from associated household dust samples. A modified “subtraction” method was also used in FastID to estimate the percentage of alleles in each dust sample contributed by known and unknown occupants. On average, 72% of autosomal SNPs were recovered from dust samples. When using FastID, (a) 93% of known occupants were detected in at least one indoor dust sample and could not be excluded as contributors to the mixture, and (b) non-contributor alleles were detected in 54% of dust samples (29 ± 11 alleles per dust sample). Overall, this study highlights the potential of analyzing human DNA present in indoor dust to detect known household occupants, which could be valuable for investigative leads.     

An innovative transfer DNA experimental design and qPCR assay: Protocol and pilot study

Forensic “touch” DNA samples are low-quantity samples that are recovered from surfaces that have been touched by single or multiple individuals. These samples can include DNA from primary contributors who directly touched the surface, as well as secondary contributors whose DNA was transferred to the surface through an intermediary. It is difficult to determine the type of transfer, or how often and under what conditions DNA transfer occurs. In this paper, we present an innovative protocol that combines (1) a paired male and female transfer DNA experimental design in which the presence of male DNA indicates secondary transfer and (2) a cost-effective quantitative PCR (qPCR) assay of a sex-specific region in the Amelogenin gene to detect male and female DNA. We evaluate the ability of the Amelogenin qPCR assay to detect low concentrations of male and female DNA in mixed samples. We also test experimental DNA samples using our transfer DNA protocol to differentiate primary and secondary DNA transfer. Male DNA was detected in the majority of known mixed samples, even in samples with 4× more female DNA—this result demonstrates the ability to detect low concentrations of male DNA and the presence of secondary transfer DNA in our experimental design. Primary DNA transfer was detected in 100% of our experimental trials and secondary DNA transfer was detected in 37.5% of trials. Our innovative protocol mimics realistic case scenarios to establish rates of primary and secondary DNA transfer in an inexpensive and simplified manner.     

The analysis of biological samples from crime scene for a future human DNA profile confrontation. Effects of presumptive test reagents on the ability to obtain STR profiles for human identification

Because of the increase of evidence of blood stains, that have been washed or cleaned in an attempt to mask the analysis of DNA profiles, there is also an increase in the use of presumptive tests on samples sent to laboratories. Some of the presumptive tests, used to identify blood and semen stains, could potentially affect the recovery of high molecular weight DNA from the samples, or extinguish them, especially those already present in small quantities. After the presumptive tests, often these samples are discarded. This study aimed to examine the possibility of obtaining a DNA profile from samples submitted for presumptive testing and cleaned with bleaches with and without chlorine. Two different protocols were conducted: (a) A unique sample of human blood in natura (5 μL), already typed through the DNA techniques with the genetic profile previously known (control), was distributed onto cotton fabrics and dried at room temperature. Four samples of fabric were macerated in saline solution and Coombs serum and then stored for three months (room temperature and freezer −20 °C). (b) Another sample of human blood, type A, in natura, already typed through the techniques of DNA (control) was used. Aliquots of 200 μL were distributed in: cotton, denim and synthetic fabric. The samples were dried at room temperature for 24 h. The blood stains in those fabrics (cotton, denim and synthetic) were then divided into three groups: unwashed, cleaned with chlorine bleach and cleaned with chlorine bleach and soap powder. The samples were again dried at room temperature for 24 h, before the use of luminol. The DNA were extracted with Chelex 100 and amplified with the Identifiler Kit (Applied Biosystems). The blood stains exposed to saline and Coombs serum had DNA profiles consistent with untreated samples (controls). This result shows that the experts should keep and store the samples treated with saline and Coombs serum for future DNA confrontation when necessary. Also discussed in this paper the pattern of blood stains after washing with bleaching solutions, as well as the quantity of DNA obtained from these samples.     

A preliminary assessment of the effect of PreCR™ DNA repair treatment on mixture ratios in two person mixtures

In this study, DNA extracted from known buccal samples was combined into two component mixture samples. These were subjected to UV exposure prior to their amplification with the Promega PowerPlex® 16HS amplification kit, and subsequent capillary electrophoresis on the ABI 3130xl instrument. Damaged samples were subjected to enzymatic repair treatment and retested to assess the amount of repair. Data showed that there is fidelity associated with the application with profile concordance after its use, and a corresponding increase in the amount of recovered alleles post damage. Results also showed changes in the stochastic relationship between mixture components that appear to be induced by the repair process itself. The mixture ratios of DNA samples were altered from an approximate original 1:3 ratio, to a ratio of 1:2 or greater. This variation can have a significant effect regarding the ability to reliably de-convolute DNA mixtures that have been subjected to the repair process.     

Using STR analysis to detect human DNA from exploded pipe bomb devices

This study investigated the possibility of recovering a bomb assembler's DNA from an exploded pipe bomb device. Metal and polyvinyl chloride (PVC) pipes were examined to determine if one surface type would allow better DNA recovery than the other. Ten subjects each handled components of one metal and one PVC pipe bomb. The bombs were exploded, the fragments were collected and swabbed using the double swab technique, and the samples were extracted, quantified, amplified, and genotyped using polymerase chain reaction/short tandem repeat (PCR/STR). Of the 20 bombs handled by the subjects, four bombs gave reportable results that matched the subject's known DNA profiles. An additional eight profiles, also matching the subject's known DNA profiles, were generated but were below the reportable threshold. There was no difference in the success rate of obtaining DNA profiles related to the use of either PVC or metal in the manufacture of the pipe bomb. The variables that appeared to have the greatest influence on the success of generating a DNA profile were the amount of fragmentation and subsequent recovery of the bomb fragments. It is suspected that successful DNA profiling could also be dependent upon the bomb assembler's propensity to slough skin cells on objects they handled.     

New optimized DNA extraction protocol for fingerprints deposited on a special self-adhesive security seal and other latent samples used for human identification

Abstract: Obtaining complete short tandem repeat (STR) profiles from fingerprints containing minimal amounts of DNA, using standard extraction techniques, can be difficult. The aim of this study was to evaluate a new kit, Fingerprint DNA Finder (FDF Kit), recently launched for the extraction of DNA and STR profiling from fingerprints placed on a special device known as Self‐Adhesive Security Seal Sticker^® and other latent fingerprints on forensic evidentiary material like metallic guns. The DNA extraction system is based on a reversal of the silica principle, and all the potential inhibiting substances are retained on the surface of a special adsorbent, while nucleic acids are not bound and remain in solution dramatically improving DNA recovery. DNA yield was quite variable among the samples tested, rendering in most of the cases (>90%) complete STR profiles, free of PCR inhibitors, and devoid of artifacts. Even samples with DNA amount below 100 pg could be successfully analyzed.     

Oligonucleotide fingerprinting using (GTG)5 and (GACA)4 probes for the differentiation of body fragments

For the detection of postmortem stability of DNA and for the identification of parts of dead bodies of unknown origin the oligonucleotide probes (GTG)5 and (GACA)4 can be used. (GTG)5 is a highly discriminating probe which allows to differentiate in the 4 to 25 kilobase range of DNA fragments. DNA fingerprints obtained by (GACA)4 show useful results especially in the short fragment range. The (GACA)4 probe can therefore be used to analyze partially degraded DNA.     

Assessing the performance of quantity and quality metrics using the QIAGEN Investigator® Quantiplex® pro RGQ kit

The Quantiplex® Pro RGQ kit quantifies DNA in a sample, supports the detection of mixtures and assesses the extent of DNA degradation based on relative ratios of amplified autosomal and male markers. Data show no significant difference in the accuracy and sensitivity of quantification between this and the Promega PowerQuant® System, both detecting the lowest amount of DNA tested, 4 pg. Laboratory controlled mixed male:female DNA samples together with mock sexual assault samples were quantified across a range of mixture ratios. Analysis software detected mixed DNA samples across all ratios for both quantification kits. Subsequent STR analysis using the Investigator® 24Plex QS Kit was able to corroborate mixture detection down to 1:25 male:female DNA ratios, past which point mixtures appeared identical to single-source female samples. Analysis software also detected laboratory degraded DNA samples, with data showing a positive trend between the Degradation Index (DI) and length of time of sonication. When used on ancient remains the assay was able to triage samples for further analysis, and STR profiles were concordant with DNA quantification results in all instances. STR analyses of laboratory-controlled sensitivity, mixture, and degradation studies supports the quality metric obtained from quantification. These data support the use of the Quantiplex® Pro RGQ kit for sample screening and quantification in forensic casework and ancient DNA studies.     

Influence of the luminol chemiluminescence reaction on the confirmatory tests for the detection and characterization of bloodstains in forensic analysis

Preliminary tests for the detection of stains at crime scenes aim to focus the police work making them more efficient in the combat of criminality. The application of the luminol chemiluminescence reaction (3-aminoftalhidrazida) in presumptive tests for the detection of bloodstains is known for more than 40 years in forensic science. This reaction is based on the emission of light through the chemical reaction of luminol mixed with hydrogen peroxide and a hydroxide in the presence of a catalytic molecule (iron from the hemoglobin) (Laux [1]).This work evaluates the luminol interference and its effect on subsequent serological and DNA testing. Samples prepared with blood and different concentrations of luminol solution containing luminol, peroxide of hydrogen and sodium carbonate, were analyzed. Additionally, samples of serial dilutions of standard DNA mixed with luminol solution were also analyzed. Although presumptive tests with luminol do not establish the characterization and identification of stains at crime scenes, preliminary results indicated that it is suitable for the detection of invisible bloodstains for forensic analysis, with few detrimental effects on the serological tests and subsequent DNA recovery and typing.     

PuriTyper~(TM)法医学纯化试剂盒的性能验证

目的验证PuriTyperTM纯化试剂盒各项性能指标和法医学应用价值。方法收集及制备抗凝血液、常见案件检材(唾液、烟头、精液、毛发、指甲、骨骼及组织块)、斑痕样本(血斑、唾液斑、精斑)以及模拟添加抑制剂和模仿自然环境中放置的血斑。采用PuriTyperTM纯化试剂盒提取纯化并进行DNA定量,IdentifilerTM复合扩增试剂盒扩增,产物经ABI 3130遗传分析仪进行检测,Genemapper软件分析结果,对该试剂盒灵敏度、稳定性、重复性、检材适应性进行测试。结果采用该试剂盒提取0.1～40μL血液分别获得0.042～26.45ng/μL的DNA。3种斑痕样本DNA产量平行试验结果稳定。不同类型检材重复检验所获IPC的CT平均值在27.60至28.03之间。常见案件检材所得分型与已知结果均一致。结论 PuriTyperTM纯化试剂盒能够满足法医DNA检验的要求,对法医学实践具有重要的应用价值。     

Victim of a dictatorial regime: identification of Mr. Roberto Gomensoro Josman

Forensic cases are ideal to test osteological techniques developed by physical anthropologists. Forensic anthropology is a scientific discipline that applies population-based standards to individual skeletal remains. Many complex techniques are used in an attempt to make a positive identification. Several of these techniques, specifically digital video superimposition and DNA, were used to identify the victim in this case. The purpose of this paper is to describe anthropological techniques used to identify the remains of an unknown person who was later identified as Mr. Roberto Gomensoro Josman, the victim of a Uruguayan dictatorial regime. Mr. Gomensoro Josman disappeared after authorities of the Uruguayan dictatorial government (1973-1984) arrested him. Six days later an unknown body was found floating in Lake Rincon del Bonete. The corpse was found tied with wire and weighted with three large stones used to keep the body submerged. An autopsy was performed and the body was buried as an unknown person in the grave identified as number 10936 of Tacuarembo Cemetery. On December 2002 the Peace and Justice Service asked the local judge to authorize the exhumation of the remains. The exhumed body was headless. An investigation revealed that the local medical examiner who had autopsied the remains on March 1973 had retained the victim's skull in his office. Osteological analysis indicated the victim was a white male in his 20s. Four good quality photographs of Mr. Gomensoro who was known to be missing were compared with the skull. To confirm the identification from the video a DNA analysis was carried out comparing the victim with relatives. DNA typing confirmed the results of the earlier identification.     

The analysis of substituted cathinones. Part 2: an investigation into the phenylacetone based isomers of 4-methylmethcathinone and N-ethylcathinone

During the analysis of "seized samples", suspected of containing 4-methylmethcathinone (mephedrone) and N-ethylcathinone (ethcathinone) additional compounds were observed in the GCMS chromatogram. These compounds were suspected to be the corresponding phenylacetone isomers of mephedrone and ethcathinone respectively. These isomers are referred to as iso-mephedrone and iso-ethcathinone, respectively. The identity of these compounds was verified by synthesising the isomers from known starting materials and comparing them with the compounds found in the seized samples. Analytical data, GCMS, NMR and IR on these compounds are provided. Possible explanations for the presence of these compounds in the seized samples are explored. Contaminated starting material is one suggestion. Rearrangement of the propiophenone based product to the phenylacetone based product is also suggested. The reaction of the α-bromopropiophenone with a primary amine can also lead to the phenylacetone based product. The presence of these isomeric compounds in seized samples could be used to compare different samples and attempt to establish a common origin.     

Grading a rape case followed by death from the study of autosomal STRs and STRs of the Y chromosome—Case study

Two women were found dead inside a residence. Choke causes death in one that had been naked in a bed and contusion injury in another that was found on a sofa. Were received samples of vaginal and anal swabs of the two victims of homicide with suspected of having suffered sexual violence. References also received samples of two victims and a suspect. We performed genetic analysis for identification of samples from the meeting of any possibility of overlap between patterns and profiles of sequences of deoxyribonucleic acid (DNA) based on genetic relationship between those involved. The reference samples were subjected to the procedure of extraction of nuclear DNA by Chelex method and the swabs samples by differential extraction. For all the samples were performed for amplification of STRs loci and autosomal STRs of chromosome Y. The profiles of DNA sequences were obtained by the Polymerase Chain Reaction (PCR), using sequences starting with marked substances emitting fluorescence detected by reading the optical laser in 3100 Avant automatic sequencer from Applied Biosystems. The information of consecutive loci of Short Repeats or STRs of autosomal chromosomes and the Y chromosome was obtained using the systems or products sold in multilocus, methodologies recommended by the supplier and valid for analysis of DNA. We used the multilocus Identifiler and YFiler system of Applied Biosystems to the amplification of samples. The validation of results has shown a genetic profile in male anal secretion of the victims with a complete coincidence with the suspect.     

Examination of Y-STR mutations in sex chromosomal abnormality in forensic cases

The Y-STR typing was carried out on eight DNA samples (three from criminal cases) demonstrating Klinefelter's syndrome. STR types in the X chromosome were randomly distributed. However, some Y-STR markers were distributed within the normal range but restricted to only one or two specific alleles, that is, some specific haplotypes were found in Klinefelter's syndrome. In addition, a single nucleotide polymorphism in DYS390 (transversion of G to A at the 28th position downstream of tandem repeats) was detected in Klinefelter samples. This Y-STR polymorphism and restricted Y-STR alleles in Klinefelter's syndrome is not known, but it might be related to the genesis of Klinefelter's syndrome. We also found that extended standard haplotypes of these samples are extremely rare in the normal population, according to the Y-STR haplotype reference database (YHRD). The extended standard haplotype database in a Japanese population is also reported. In 100 unrelated Japanese, 89 haplotypes were observed, and the haplotype diversity was calculated to be 0.9866.