The application of infrared chemical imaging to the detection and enhancement of latent fingerprints: method optimization and further findings

Fourier transform infrared (FTIR) chemical imaging allows the collection of fingerprint images from backgrounds that have traditionally posed problems for conventional fingerprint detection methods. In this work, the suitability of this technique for the imaging of fingerprints on a wider range of difficult surfaces (including polymer banknotes, various types of paper, and aluminum drink cans) has been tested. For each new surface, a systematic methodology was employed to optimize settings such as spectral resolution, number of scans, and pixel aggregation in order to reduce collection time and file-size without compromising spatial resolution and the quality of the final fingerprint image. The imaging of cyanoacrylate-fumed fingerprints on polymer banknotes has been improved, with shorter collection times for larger image areas. One-month-old fingerprints on polymer banknotes have been successfully fumed and imaged. It was also found that FTIR chemical imaging gives high quality images of cyanoacrylate-fumed fingerprints on aluminum drink cans, regardless of the printed background. Although visible and UV light sources do not yield fingerprint images of the same quality on difficult, nonporous backgrounds, in many cases they can be used to locate a fingerprint prior to higher quality imaging by the FTIR technique. Attempts to acquire FTIR images of fingerprints on paper-based porous surfaces that had been treated with established reagents such as ninhydrin were all unsuccessful due to the swamping effect of the cellulose constituents of the paper.     

Four new illicit cocaine impurities from the oxidation of crude cocaine base: formation and characterization of the diastereomeric 2,3-dihydroxy-3-phenylpropionylecgonine methyl esters from cis- and trans-cinnamoylcocaine

Four new impurities have recently been detected in the gas chromatographic signature profiles of many illicit cocaine hydrochloride exhibits. These impurities are only seen in exhibits that have been oxidized and are most prominent in samples that have been highly oxidized. Exhibits containing these compounds were subjected to gas and liquid chromatographic-mass spectrometric analyses to determine the identity of the impurities. These impurities were subsequently synthesized to verify their structures. Four diastereomeric diols formed from the oxidation of cis- and trans-cinnamoylcocaine were characterized by nuclear magnetic resonance spectrometry, mass spectrometry, and synthesis. Oxidation of cis-cinnamoylcocaine in neutral conditions yielded (2R,3R)-dihydroxy-3-phenylpropionylecgonine methyl ester and (2S,3S)-dihydroxy-3-phenylpropionylecgonine methyl ester, while trans-cinnamoylcocaine produced (2R,3S)-dihydroxy-3-phenylpropionylecgonine methyl ester and (2S,3R)-dihydroxy-3-phenylpropionylecgonine methyl ester. The recent appearance of these new impurities suggests that some illicit cocaine processors have modified their oxidation procedures of crude cocaine base for transformation into illicit refined cocaine hydrochloride.     

Fentanyl concentrations in 23 postmortem cases from the hennepin county medical examiner's office

The purpose of this study was to compare blood fentanyl concentrations in fentanyl-related deaths with fentanyl concentrations found incidentally at autopsy, as well as with fentanyl concentrations found in hospitalized patients receiving fentanyl. Between the years 1997 to 2005, 23 fentanyl-positive postmortem cases were identified. Nineteen of 23 (82.6%) cases were deemed to be drug overdoses. Fentanyl alone was responsible for 8 of the 19 (42.1%) overdose deaths. Mean and median fentanyl concentrations were 36 (SD 38) microg/L and 22 microg/L, respectively, range 5-120 microg/L. Seven of the cases were accidental, one undetermined. The remaining 11 of the 19 (57.9%) cases were mixed drug overdoses. Fentanyl concentrations in these cases were 31 (SD 46) microg/L, range 5-152 microg/L. All of the mixed drug overdoses were determined to be accidental. Four cases where fentanyl was considered an incidental postmortem finding were determined to be natural deaths. In hospitalized inpatients (n = 11) receiving fentanyl 2 of the patients receiving fentanyl for chronic pain for more than 3 months had concentrations of 8.5 microg/L and 9.9 microg/L. The other nine inpatient concentrations were less than 4 microg/L. In conclusion, blood fentanyl concentrations found in cases where fentanyl alone was determined to be the cause of death were similar to cases where fentanyl was part of a mixed drug overdose. There was also considerable overlap between fentanyl concentrations in fentanyl-related overdose deaths compared to hospitalized patients being treated for chronic pain. Fentanyl concentrations in postmortem cases must be interpreted in the context of the deceased's past medical history and autopsy findings.     

钾中毒死亡家兔的尸体化学变化

目的研究家兔钾中毒死亡后的尸体化学变化特征,为钾中毒的法医学鉴定提供参考。方法采用浓度为0.3%和1%的KCl葡萄糖溶液分别以全速和100滴/min的速度输给家兔,至其死亡,测定家兔输液前后血、尿电解质浓度,比较两种不同输液方式所致钾中毒死亡后尸体化学变化特征。结果输钾前后,家兔血清K (SK)浓度升高,血清Na 、Ca2 、Cl-及HCO3-浓度均降低,全血K (TK)及血清Mg2 浓度变化无显著性差异。0.3%KCl组致死输液时间长于1%组(P=0.006),致死输钾量无显著性差异(P=0.062);TK、血清Na 、Mg2 及Cl-浓度变化值具有显著差异,SK、Ca2 、HCO3-浓度变化值无显著差异;尿量和尿液各电解质浓度指标未见显著性差异。结论尸体SK、TK及血清Mg2 浓度升高,有助于钾中毒的法医学死后诊断。     

脑血管造影在法医学尸体检验中的应用

脑血管造影作为诊断脑血管疾病的"金标准",目前已经广泛地应用于临床医疗活动中,并积累了丰富的理论和实践资料,是趋于成熟的技术方法。由于因脑血管疾病引发的法医学鉴定案件较为多见,故该技术近年开始应用于法医学,显示出在法医学实践中独特而重要的应用价值。本文对脑血管造影术在法医学中的应用价值进行综述,内容包括辅助定位血管病变或损伤部位、明确出血性质、指导尸体解剖与脑组织病理取材等,并在此基础上展望了该技术在法医学中的应用前景。     

Predicting the Postmortem Submersion Interval for Human Remains Recovered from U.K. Waterways*

Abstract: This article aims to increase accuracy in estimating the postmortem submersion interval (PMSI) for bodies recovered from rivers in the United Kingdom. Data were collected from closed case files, crime scene reports, and autopsy files concerning bodies recovered over a 15‐year period from the River Clyde, Scotland, and the River Mersey and canals in northwest England. One hundred and eighty‐seven cases met the study criteria and were scored by quantifying the overall amount of decomposition observed in each case. Statistical analysis showed that the duration of a body’s submergence in water and the temperatures to which it was exposed, as measured in accumulated degree days (ADD), had a significant effect on the decay process. Further analysis indicated that there were no significant differences in decomposition between the waterways. By combining the data from all study samples, it was possible to produce a single linear regression model for predicting ADD from observed decomposition.     

Death of a 10‐Month‐Old Boy After Exposure to Ethylmorphine

Abstract: Ethylmorphine, an opiate that is partially metabolized to morphine, is a common ingredient in antitussive preparations. We present a case where a 10‐month‐old boy was administered ethylmorphine in the evening and found dead in bed the following morning. Postmortem toxicological analyses of heart blood by gas chromatography‐mass spectrometry and liquid chromatography‐mass spectrometry revealed the presence of ethylmorphine and morphine at concentrations of 0.17 μM (0.054 mg/L) and 0.090 μM (0.026 mg/L), respectively. CYP2D6 genotyping showed that the deceased had an extensive metabolizer genotype, signifying a “normal” capacity for metabolizing ethylmorphine to morphine. The autopsy report concluded that death was caused by a combination of opiate‐induced sedation and weakening of respiratory drive, a respiratory infection, and a sleeping position that could have impeded breathing. This is the first case report where the death of an infant has been linked to ethylmorphine ingestion.     

Vitreous Humor: Biochemical Constituents in Estimation of Postmortem Interval*,†

Abstract: Analysis of biochemical constituents of the vitreous humor can be useful in determining the postmortem interval as there is proportionate postmortem rise of potassium and fall in sodium concentration. We studied 120 autopsy cases to determine the utility of potassium, sodium, calcium, and chloride levels, and sodium/potassium ratio in estimating the postmortem interval. There was a linear relationship between vitreous potassium concentration and postmortem interval, whereas an inverse relationship between vitreous sodium/potassium ratio and postmortem interval was noted. Other factors like age, sex, cause of death, season of death, and refrigeration of sample did not influence the vitreous humor potassium values. Using the statistical tools, a new formula was derived to determine the postmortem interval based on the potassium concentration and a review of previous literature is presented. Hence, the findings of this study supported a central role of vitreous humor biochemistry in many postmortem forensic and pathological evaluations.     

Preliminary Studies into the Characterization of Chemical Markers of Decomposition for Geoforensics*

Abstract: In this paper, we report the results of our preliminary studies into chemical characterization of the fluids produced during decomposition in the absence of a soil matrix. Pig (Sus domestica) carcasses were used to model the human decomposition process in two separate locations, Western Australia (Perth) and Canada (Oshawa). Analysis involved simple dilution and filtration of the decomposition fluids followed by gas chromatography–mass spectrometry. Several previously unreported compounds were detected in the decomposition fluid samples during the trials, including benzeneacetic acid, benzenepropionic acid, 2‐piperidone, and isocaproic acid. Possible biosynthetic pathways for some of the compounds produced are proposed. Further research trials are required, particularly in the presence of soil matrices.     

利用嗜尸性蝇类生活史推测死亡时间

目的积累一些嗜尸性蝇类生活史的资料及群落组成的季节性变动规律。方法采用动物尸体作诱饵,分别对自然飞到诱饵上繁殖生长的8种嗜尸性蝇类的生活史及群落组成的季节性变动规律进行观察研究。结果夏季高温时段蝇类群落组成物种较为丰富,冬季低温时段蝇类种群较为单一。常见8种嗜尸性蝇类虫态经历时间在气温高时较短,气温低时较长。结论嗜尸性蝇类生活史及群落组成的季节性变动规律可为推测死亡时间提供依据。