From 2012 to 2014 in Japan, a total of 214 cases of motor vehicle collisions were attributed to the use of illegal drugs by drivers. In 93 out of 96 investigated cases, the causative agents were 22 kinds of synthetic cannabinoids (SCs). Those SCs can be grouped into three groups according to the timeline of use and their chemical structures. The first generation SC naphtoyl indole derivatives, such as MAM-2201, were used in 2012 and disappeared by governmental overall regulations in Spring, 2013. Instead, quinolinyl ester indoles (second generation SC, such as 5F-PB-22) and indazole carboxamides (third generation SC, such as 5F-AB-PINACA) appeared thereafter with much stronger potencies. An outbreak of SC occurred in Summer, 2014 with one of the strongest SCs, 5F-ADB. The common signs observed in the SC-abused drivers are impaired consciousness, anterograde amnesia, catalepsy with muscle rigidity, tachycardia, and vomiting or drooling. Since the third generation SCs are extremely potent CB1 agonists (only a small amount is required) and instable in blood, it is very difficult to detect SCs in biological samples. Actually, only in one third of the cases, SC could be detected in blood or urine.
Offline writer verification is an important security measure and is related to human traits. However, even with modern techniques, maximizing the amount of information from the limited number of available samples remains a challenging task. We propose a new offline writer verification system inspired by the expertise of forensic document examiners. The system combines the shape and pen pressure information in multiple characters captured by a multiband image scanner. From the visible images, the shape information is extracted as a weighted direction code histogram, and the local pen pressure information (which is based on ink intensity) is extracted as local directional pattern features with adaptive zoning. From the infrared images, the global pen pressure information (which is based on the writing indentations) is extracted as first- and second-order texture statistics. In an experimental comparison study at less than 0.1% error rate, the proposed system reduced the number of required Japanese Kanji characters from six (in the conventional system) to three. After combining these techniques, the error rate per character (averaged from 54 volunteers) was reduced from 4.8% in the conventional method to 1.3%.
Three analogues of 1-phenyl-2-(pyrrolidin-1-yl)pentan-1-one (α-PVP), 1-(4-fluorophenyl)-2-(pyrolidin-1-yl)pentan-1-one (4F-α-PVP), 1-(4-methoxyphenyl)-2-(pyrrolidin-1-yl)pentan-1-one (4MeO-α-PVP) and 2-(pyrrolidin-1-yl)-1-(thiophen-2-yl)pentan-1-one (α-PVT), and their metabolites were determined in users' urine by liquid chromatography-tandem mass spectrometry using newly synthesized authentic standards. The identified metabolites indicated that metabolic pathways of three α-PVP analogues include the reduction of the carbonyl group to the corresponding alcohols and the oxidation of the pyrrolidine ring to the corresponding pyrrolidone, and 4MeO-α-PVP and α-PVT have additional metabolic pathways of the O-demethylation and the oxidation of thienyl group respectively. The quantitative analyses of the urinary metabolites suggested that the main metabolic pathways of these α-pyrrolidinophenones (PPs) derivatives could vary largely depending on the aromatic rings or substituent groups on the aromatic ring of PPs.
Author identification through text-mining aims to judge whether an author suspected of writing a certain text is same as that of control texts. This study examined the validity of scoring for author identification. In one unit of analysis, we conducted 18 analyses (six writing styles×three multivariate analyses) across one suspected text of a blogger, one control text of a blogger, and irrelevant texts of four bloggers. The writing style factors were (1) rate of usage of non-independent words, (2) bigram of parts-of-speech, (3) bigram of postpositional particles, (4) positioning of commas, (5) rate of usage of Kanji, Hiragana, etc. and (6) sentence length. We completed (1) principal components analysis, (2) corresponding analysis, and (3) multi-dimensional scaling. We obtained scores from arrangements of texts on two dimensions, convex hull polygon (CHP) consisting of control texts was overlapped with that of irrelevant texts (a score of 0). Besides not overlapping each CHP of control and irrelevant texts, (a score of +2) a suspected text arranged into CHP of control texts, (a score of +1) one not arranged into CHP of control texts but near a control text, and (a score of −1) one near an irrelevant text. We totaled the scores in one unit of analysis (18 results) and analyzed the total scores of the 240 units of analysis for 10 bloggers under the following design: 2 (author combination of suspected and control texts: same, different)×4 (number of characters: 250, 500, 1000, 1500)×3 (number of control and irrelevant texts: 3, 6, 9). The results indicated the scoring method was able to identify the authors. AUCs of number of characters were statistically significant, but the number of texts was not significant. Furthermore, rate of usage of non-independent words and parts-of-speech were quite useful to identify authors.
In this study, we describe a rapid gas chromatography-tandem mass spectrometry (GC-MS/MS) analytical method that allows comprehensive detection and structural elucidation of synthetic cathinone-type designer drugs. Our proposed method consists of three simultaneous analytical procedures: 1) selective detection of the carbonyl group characteristic to each cathinone examined via selected reaction monitoring (SRM); and the determination of both 2) iminium cations and 3) substituted benzoyl cations generated via the α-cleavage of their corresponding amines and ketone moieties via product ion scanning, respectively. One peak was detected in the SRM chromatogram for all cathinones examined in procedure 1), as well as the relevant single peaks in the total ion current chromatograms that resulted from procedures 2) and 3) at the same retention time. SRM of procedure 1) showed the transition of substituted benzoyl cations to substituted phenyl cations due to CO elimination, revealing the presence of carbonyl groups within the structures. Each product ion spectrum of the substituted benzoyl cation allowed for both determination of which group was substituted on the aromatic ring and differentiation between corresponding positional isomers for ethyl, methoxy and methylenedioxy substitution. However, identification of the substitution positions for the methyl, bromine and fluorine groups on the aromatic ring was difficult. On the other hand, differences between structural isomers in the product ion spectra of iminium cations were clearly identifiable, allowing for easy discrimination between isomers.
Several synthetic cannabinoids such as AM-2201 contain the 3-carbonyl-N-fluoropentylindole structure. This structure has fluorine positional isomers on the alkyl chain. In most cases, legal controls are placed only on the 5-fluoro analogue. Thus, differentiation of isomers is a significant issue in forensic science. In this study, we developed a method for the differentiation of positional isomers of 3-carbonyl-N-fluoropentylindole derivatives utilizing multiple-stage mass spectrometry using an ion trap tandem mass spectrometer. In addition, the analogues whose fluorine atom was replaced with a chlorine atom or hydroxyl group were also examined. With respect to each positional isomer of fluorine and chlorine, the ion at m/z 232 or m/z 248, obtained by MS2 analysis of [M＋H]+, were selected as the precursor ions for MS3 analysis. The ion at m/z 232 and m/z 248 corresponded to the 3-carbonyl-N-fluoropentylindole and 3-carbonyl-N-chloropentylindole structures. Furthermore, the ion at m/z 212, corresponding to the de-halogenated fragments of the 3-carbonyl-N-fluoropentylindole- and 3-carbonyl-N-chloropentylindole-structures, was selected as the precursor ion for MS4 analysis. Consequently, combination of these MSn analysis achieved differentiation of all the positional isomers. With respect to positional isomers with the hydroxyl group, however, the fragment ion at m/z 212 was not observed from the MS3 analysis of m/z 230, which corresponds to the 3-carbonyl-N-fluoropentylindole structure. Therefore, differentiation of each positional isomer was not achieved by MSn analysis. This method is useful for the differentiation of positional isomers of 3-carbonyl-N-fluoropentylindole and 3-carbonyl-N-chloropentylindole derivatives.
We present herein a practical methodology for elucidating the o-, m-, or p-fluorine substitution pattern of indazole-type synthetic cannabinoids containing a fluorobenzyl group at the N-1 position and a carbonyl group at the C-3 position via electron ionization-triple quadrupole mass spectrometry. We synthesized, as model compounds of the synthetic cannabinoids, the o-, m-, and p-fluorine positional isomers: 1-[1-(2-, 3-, and 4-fluorobenzyl)-1H-indazol-3-yl]ethanone (o-, m-, and p-FUBINAE). Mass spectral analyses showed that the three isomers differed significantly in the logarithmic values of the abundance ratios of the product ion at m/z 109 to the precursor ion at m/z 253 (ln(A109/A253)), following the order of meta<ortho<para. In addition, the relationships between ln(A109/A253) and collision energy were linear with high correlation coefficients. Comparing the ln(A109/A253) plots of the FUBINAE isomers versus collision energy with similar plots of AB-FUBINACA and its o- and m-fluorobenzyl isomers showed that the three AB-FUBINACA isomers behaved as the FUBINAE isomers did with the same fluorine substitution pattern on the phenyl ring. Moreover, other synthetic cannabinoids with a p-fluorobenzyl group (ADB-FUBINACA, FUB-AMB, FUB-APINACA, FUB-NPB-22, and FU-PX-2) also exhibited behavior similar to p-FUBINAE. These results indicated that the fluorine substitution position on the phenyl ring can be differentiated by collating the model compounds according to the logarithmic plots of their mass spectral abundance ratios as a function of the collision energy.
In criminal investigations, writer-identification to discriminate writers of documents used in crimes has important roles. In the identification processes, writer-unknown documents are compared with writer-known documents. Experts of the process give careful considerations for the comparisons by referring to handwriting-samples, experimental-data, and other vast knowledge collected from past investigations. Characteristics of handwritten strokes written on the documents are highly useful for the experts. Therefore, accurate and efficient managements of the characteristics are important. However, in the daily investigations, the characteristics have been recorded in a huge amount of paper media without indexes, and the amount is growing. In this paper, we propose two prototypes of database system to store and retrieve the characteristics. The database system consists of (1) common digital formats to indicate the characteristics, (2) aggregation functions of the digital indicators for the retrieval, and (3) user interface for the experts. The first prototype is implemented with VBA of Microsoft Excel. We present our experimental results by using 228 testing data sets. The second practical prototype is implemented with XML and Java. We expect that our database system will improve the efficiency and the accuracy of the writer-identification processes, and accelerate information sharing among the experts beyond time and space.
Human behavior is characterized by inherent regularity, and previous studies have confirmed that criminal behavior is no exception. In particular, three distinguishable aspects of geographic offending behavior may be characterized by consistency: destination, distance, and direction. In this study, which focused on the aspect of direction, we carried out Van Daele and Bernasco's (2012) additional tests concerning residential burglary cases in Japan. Similar to Van Daele and Bernasco, we proposed the directional consistency could be verified by mean angulation calculated with the average angle between all possible pairs of offenses in a series and compared these to the thresholds that were simulated using the angles chosen at random by the previous authors. Our results confirmed directional consistency in the cases of residential burglary in Japan. We expect this information will improve the accuracy of estimating the location of the offender's residence in geographic profiling. However, the offenders did not show as much consistency as those observed in the previous study. Furthermore, these findings do not take into account preferences in crime patterns or the environmental characteristics. Therefore, it is necessary to verify the impact of these factors on directional consistency.