Errors in the estimation of the distance of fall and angles of impact blood drops.

This paper presents derived equations for the estimation of the variances in the estimated distance of fall and the estimated angle of impact for blood droplets. The derived equation for the variance of the estimated distance of fall predicts that as the blood drop size approaches that of a blood droplet falling at terminal velocity, the variance of the estimate grows without limit. The derived equation for the variance in the estimated angle of impact shows that as the angle of impact approaches 90 degrees, the variance grows without limit. The validity of the equation for the estimated variance of the angle of impact was tested for five angles of impact (15, 30, 45, 60 and 75 degrees); the equation correctly predicted the observed variance up to an angle of 60 degrees.     

Deducing drop size and impact velocity from circular bloodstains

An experimental study was done to determine the diameter and velocity of blood drops falling on a surface by measuring the size of bloodstains they produced and counting the number of radial spines projecting from them. Bloodstains were formed by releasing drops of pig blood with a range of diameters (3.0-4.3 mm) and impact velocities (2.4-4.9 m/s), onto four different flat surfaces (glass, steel, plastic, paper) with varying roughness (0.03-2.9 microm). High-speed photography was used to record drop impact dynamics. Bloodstain diameters and the number of spines formed around the rim of stains increased with impact velocity and drop diameter. Increasing surface roughness reduced stain diameter and promoted merging of spines, diminishing their number. Equations are presented that explicitly relate drop diameter and impact velocity to measurements of stain diameter and number of spines.     

圆形滴状血迹形态与血滴体积、撞击速度的相关性

目的观察不同体积的血滴以3种撞击速度垂直撞击3种不同介质形成的滴状血迹形态及大小,并探讨其相关性。方法将8种不同体积（14～115IxL）的抗凝猪m形成血滴,以3种不同的撞击速度（3．1～5．4m／s）分别垂直滴落于白纸、玻璃及釉面地砖上,观察形成血迹的形态特征,测量其直径,并采用SPSS13．0统计软件进行分析。结果在3种撞击速度条件下,在3种介质上形成的滴状血迹直径均随血滴体积的增加而增大,血迹直径与血滴体积存在较好的线性关系,可得出回归方程（回归模型R2〉0．85,P〈0．01）;介质表面越粗糙,血迹直径越小;仅在自纸上发现血迹边缘有突起形成,且其数目随血滴体积的增加而增多。撞击速度及血滴体积存在较好的多重线性关系,可得出多重回归方程（回归模型R2〉0．90,P〈0．01）。结论垂直撞击形成的血迹形态及大小与血滴体积、撞击速度具有显著的相关性,可望用于推测出血源位置、受伤体位及出血部位载体。     

Spatial position of the cranium in craniofacial establishment of identity

A total of 90 images of male cranes from different groups of horizontal profiling (120 +/- 10 degrees, 140 +/- 10 degrees, 160 +/- 10 degrees) were studied in experiment with the coordinate-controlled complex for turning angle (from the position full face to the right and left by 14 degrees with spacing 2 degrees). Each image was marked according to the system of 18 control points. Precision of the angle fixation was 0.1 degrees. Calculation of the angles of horizontal profiling and turning of the crane were made according to a specially devised program INPUTTING. Statistic processing of the computer data base made it possible to calculate precision rates of marking points and regression equation describing the pattern of cranial control points in turning. It is shown that presicion of the turning angle estimation with reference to horizontal profiling is much higher than without it. Basing on the data obtained a method of zeroing of coordinates of the control points (placing in position for correct scaling of the objects of craniofacial identification) was devised. The method allows greater reliability of the results of personal craniofacial identification.     

Fundamental studies of bloodstain formation and characteristics

A detailed understanding of blood droplet impact dynamics and stain formation is an essential prerequisite to the interpretation of both individual bloodstains and spatter patterns. The current literature on theoretical models for the spreading and splashing of liquid drops on surfaces relevant to the forensic context of bloodstain formation has been reviewed. These models have been evaluated for a paper substrate using experimental data obtained as function of droplet size, impact velocity and angle. It is shown that for perpendicular impact there are fairly simple mathematical models for the spreading diameter and the number of scallops or spines formed around the stain though these have quite limited ranges of validity in their basic form. In particular, predictions for the diameter are best for small droplets impacting at high velocity and the number of spines saturates for higher impact velocities. In the case of spreading, a modification to the energy conservation model is found to provide excellent agreement with experimental stain diameters across a wide range of impact velocities. For non-perpendicular impact, the width of stains is found to depend principally on the normal component of impact velocity and may be predicted by an appropriate modification to the expression for the perpendicular case. Limitations in the calculation of impact angle from the stain aspect ratio are identified and a theoretical basis for the prediction of spines around an elliptical stain is proposed. Some key issues for future research are identified which include a systematic, quantitative study of the effect of surface properties on bloodstain formation.     

金属硫蛋白1A和2A的mRNA时序性表达(英文)

目的研究大鼠肌肉挫伤后金属硫蛋白(metallothionein,MT)1A m RNA、MT2A m RNA的时序性表达。方法 54只SD大鼠被分成挫伤组(挫伤后0.5、1、6、12、18、24、30和36 h组各6只)和对照组(6只)。所有总RNA均取自大鼠的骨骼肌。利用SYBR GreenⅠ法进行RT-q PCR检测大鼠挫伤骨骼肌中MT1A m RNA、MT2A m RNA的相对表达量。结果 MT1A m RNA、MT2A m RNA在损伤后的变化趋势与损伤时间具有一定的相关性。除了挫伤后0.5 h组外,其余各组MT1A m RNA、MT2A m RNA的表达量与对照组相比差异均有统计学意义(P0.05)。损伤后1 h、6 h、12 h、18 h MT1A m RNA和MT2A m RNA的相对表达量呈现逐渐上升的趋势,在18 h时达到了峰值,分别为对照组的(239.41±15.20)倍和(717.42±50.76)倍;损伤后24 h时两者的表达量均明显减少;损伤后30 h再次上升,随后下降。结论 MT1A m RNA、MT2A m RNA可能对损伤时间推断有一定的意义。     

LC-MS/MS analysis of pholedrine in a fatal intoxication case

Pholedrine (4'-hydroxymethamphetamine) is a cardiovascular agent exerting hypertensive and adrenergic effects. High doses may cause a drop in the peripheral circulation blood flow and increase blood pressure, heart rate and body temperature up to a state of central respiratory paralysis. A 15-year-old girl who suffered from heavy agitation and hallucinations was admitted to the intensive care unit in a comatose state. The clinical findings included a maximum heart rate of 170 bpm and a body temperature of 43.8 degrees C. Resuscitation measures were in vain and abandoned after approximately 2h. A toxicological emergency analysis using GC/MS revealed a considerable amount of pholedrine in blood and urine. A method for determining pholedrine in human body fluids utilizing high-performance liquid chromatography (HPLC)/tandem mass spectrometry (LC-MS/MS) with a turbo ion-spray source was developed, using D11-methamphetamine and D5-methylenedioxymethamphetamine as internal standards. Samples were prepared by SPE extraction using SPEC-C18AR/MP3((R)) columns, which yielded the best extraction recovery (67%). Chromatographic separation was achieved at pH 5 on an RP-18 stationary phase applying gradient elution from 50 to 70% of B (methanol/acetonitrile 3/1 (v/v), 0.02% acetic acid) in A (5mM ammonium acetate/acetonitrile 95/5 (v/v), 0.02% acetic acid). Supra-pure acetic acid was added to the post-column effluent with a flow rate of 0.2 microl/min to optimize ionization. Detection was carried out in the positive ionization, multiple reaction monitoring (MRM) mode. The chromatograms showed no interference from other substances. The limit of detection (LOD, S/N=3) of pholedrine was 0.8 ng/ml and its lower limit of quantification (LLOQ, S/N=10) 3ng/ml. The calibration curve was linear (r=0.999) in the range 1-100 ng/ml. Samples with higher concentrations were diluted to suit the working range. The intra-day R.S.D. between 5 and 80 ng/ml were 3.8-8.7% and the inter-day R.S.D. between 5 and 100 ng/ml were 6.7-10.7%. The pholedrine concentrations in blood and urine collected when the girl was still alive were 16.1 microg/ml (R.S.D. 10.5%) and 1120 microg/ml (R.S.D. 8%), respectively. In post-mortem samples, they were 23.0 microg/ml (R.S.D. 5.1%) in heart blood and 27.3 microg/g (R.S.D. 6.6%) in the liver.     

A new marker for estimation of bloodstain age by high performance liquid chromatography.

The applicability of a new marker for estimation of bloodstain age by reverse-phase high performance liquid chromatography (HPLC) is described. Using a microBondasphere C18 column with a two step linear gradient of 10.5-46.25% acetonitrile in 0.1% trifluoroacetic acid, an intriguing peak (unidentified) at a retention time of about 5 min was observed on chromatograms from human adult bloodstains and designated as 'X'. The area of this peak, which could be detected in extracts of bloodstains, but not in their fresh whole blood, increased with time. The ratios of the X area to heme area in bloodstains stored at room temperature and 4 degrees C for up to 52 weeks old linearly correlated with stain age by plotting on a double logarithmic scale. In bloodstains exposed to fluorescent light at room temperature, the regression equation calculated from the ratios (Rx) and the ages of stains in weeks (W) is ln(1000.Rx) = 1.1084 + 0.3937.ln(7.W), and the coefficient of correlation (r) is 0.9776 (n = 144, P < 0.001). When stains were stored at 37 degrees C, the ratio transformed into logarithms correlated linearly with stain age. The regression equation describing the relationship in bloodstains exposed to fluorescent light at 37 degrees C is ln(1000.Rx) = 2.4477 + 0.0866.W (r = 0.9826, n = 144, P < 0.001). The results of the present study suggest that the HPLC method may be applicable to the estimation of bloodstain age.     

Wind-drag estimation in a traffic accident involving a motor scooter and a tractor-trailer

This case report describes a noncontact traffic accident involving a motor scooter and a tractor-trailer with a focus on the wind-drag effect. We used load cells to measure the drag force acting on a substantially similar motor scooter when a substantially similar tractor-trailer passes by it, taking into consideration various speeds of the tractor-trailer and distances between the two vehicles. A three-dimensional steady-state flow analysis was also performed by using the CFX program for computational fluid dynamics to examine the streamlines and the pressure distribution around the tractor-trailer at various speeds. From the experiment, for a separation distance of 1.0 m (3.28 ft) and a speed of 90 km/h (55.9 mph), the maximum resultant drag force is 124.5 N (28 lb); this constitutes a degree of force that could abruptly disrupt the stability in maneuvering by an operator who is unaware of the approaching tractor-trailer. In addition, a single equation that relates the tractor-trailer speed to the drag force that acts on the motor scooter was derived on the basis of the Reynolds number (Re) and the wind-drag coefficient (C(d)): C(d) = 1.298 × 10(-7) Re.     

Quantitative Differentiation of Bloodstain Patterns Resulting from Gunshot and Blunt Force Impacts

Bloodstain pattern analysis (BPA) provides significant evidentiary value in crime scene interpretation and reconstruction. In this work, we develop a quantitative methodology using digital image analysis techniques to differentiate impact bloodstain patterns. The bloodstain patterns were digitally imaged and analyzed using image analysis algorithms. Our analysis of 72 unique bloodstain patterns, comprising more than 490,000 individual droplet stains, indicates that the mean drop size in a gunshot spatter pattern is at most 30% smaller than the mean drop stain size in blunt instrument patterns. In contrast, we demonstrate that the spatial distribution of the droplet stains—their density as a function of position in the pattern—significantly differs between gunshot and blunt instrument patterns, with densities as much as 400% larger for gunshot impacts. Thus, quantitative metrics involving the spatial distribution of droplet stains within a bloodstain pattern can be useful for objective differentiation between blunt instrument and gunshot bloodstain patterns.     

Passive Drip Stain Formation Dynamics of Blood onto Hard Surfaces and Comparison with Simple Fluids for Blood Substitute Development and Assessment,

The spreading dynamics of blood dripping onto hard surfaces is compared to two spreading models. Samples of human blood, porcine blood, and Millipore^® water were dripped onto cardboard, foamcore, and glass surfaces in low velocity passive drip simulations. Final stain diameter, the total number of spines and scallops, and angle of impact were measured and analyzed. Spreading is best predicted by applying the concept of effective viscosity to the Scheller and Bousfield (R² = 0.91) and Roisman (R² = 0.89) spreading models. In the tested conditions, blood spreads with Newtonian tendencies; however, has quantifiable differences in stain appearance to Newtonian fluids like water. This is encouraging for the development of water‐based fluids as synthetic blood substitutes (SBSs). The work presents an assessment platform to quantify and score the performance of simple water‐based fluids using final stain diameter (6 points) and number of spines and scallops (6 points) at six dripping heights between 20 and 120 cm. The angle of impact of a stain alone is not a sensitive measure of SBS performance, but stain formation scores the SBS's performance with another 1 point. Together these features generate a quantitative relative ranking system, of a maximum possible 13 points, that can be used to support the use of a particular fluid for the creation of a drip stain. The performance of twenty simple fluids in the simulated dripping assessment test is described.     

Volume Determination of Fresh and Dried Bloodstains by Means of Optical Coherence Tomography

The volume of bloodstains found on crime scenes may help forensic investigators reconstruct the location and kinematics of bloodletting events, as stain size, volume, and impact velocity are related. Optical coherence tomography was used as a method to determine the volume and volume ratio of dried and fresh bloodstains on both glass and irregular surfaces or deposited with an impact velocity. The volume of blood drops deposited on smooth glass surfaces was measured within a deviation of 2%. This deviation increased for droplets on irregular surfaces or deposited with an impact velocity. The volume ratio of dried and fresh bloodstains was equal to 19–28% depending on the individual donor and on the use of an anticoagulant. Optical coherence tomography is a good method to determine the volume of fresh and dried bloodstains in laboratory conditions and allows accurate determination of the dry/fresh ratio.     

Impact Spatter Bloodstain Patterns on Textiles

There are few reports of studies of impact spatter on textiles even though bloodstained textiles are found at many violent scenes. Impact spatter was deposited at 90° impact angle onto three knit fabrics of different yarn sizes and on paper. The resulting stain areas and number of stains were measured using ImageJ and compared with stains on paper using one‐factor ANOVA. The number of stains observed and their areas on the knit fabrics decreased as the yarn size increased. It was also found that blood that deposited on the fabric wicked only in the direction of the fibers at that location within the fabric which led to distorted stain shapes. Fewer observed impact spatter stains were found on cotton jersey knits for fabrics made with larger yarns than on paper. As the yarn size became smaller, the number of stains became the same as on paper.     

Necessity and death: lessons from Latimer and the case of the conjoined twins

The availability of the defence of necessity in cases of homicide is a complex issue in both Canadian and British jurisprudence. This article examines the divergent judicial and academic views and argues that, while necessity may be available for certain kinds of homicide, it should be rejected as a legitimate defence to intentional killings. The author looks closely at two recent cases in which the question arose as to whether or not killing a human being is ever justifiable or excusable on the basis of necessity: the Canadian case of R. v. Latimer and the British case of Re A (Children). The author argues that the approach of the Latimer court is preferable, advancing this position from a number of angles. Underlying rationales for the defence of necessity in Anglo-Canadian jurisprudence are examined, as well as the conceptually similar defence of duress, both at common law and in s. 17 of the Criminal Code. Both of these points are reinforced and analyzed via a discussion of the sanctity-of-life principle in Canadian criminal law. The article makes clear the essential nature of the issues raised in both Latimer and Re A (Children), as they engage fundamental questions of value for our society.     

Prediction of Projectile Ricochet Behavior After Water Impact*

Abstract: Although not very common, forensic investigation related to projectile ricochet on water can be required when undesirable collateral damage occurs. Predicting the ricochet behavior of a projectile is challenging owing to numerous parameters involved: impact velocity, incident angle, projectile stability, angular velocity, etc. Ricochet characteristics of different projectiles (K50 BMG, 0.5‐cal Ball M2, 0.5‐cal AP‐T C44, 7.62‐mm Ball C21, and 5.56‐mm Ball C77) were studied in a pool. The results are presented to assess projectile velocity after ricochet, ricochet angle, and projectile azimuth angle based on impact velocity or incident angle for each projectile type. The azimuth ranges show the highest variability at low postricochet velocity. The critical ricochet angles were ranging from 15 to 30°. The average ricochet angles for all projectiles were pretty close for all projectiles at 2.5 and 10° incident angles for the range of velocities studied.     

Estimation of postmortem interval using kinetic analysis of the third component of complement (C3) cleavage

To estimate postmortem interval (PMI), spontaneous cleavage of the third component of complement (C3) was studied in aged blood and cadaveric blood by crossed immunoelectrophoresis. Using the kinetics of C3 cleavage in vitro described as dC/dt = -kC, where C is the concentration of native C3 at time t and k is a first-order rate constant, Arrhenius' equation, and another equation which assumes a linear drop of body temperature after death, the percentages of C3 cleavage were calculated. There was a significant positive correlation between the calculated percentages and the measured percentages of up to 10% in cadaveric blood. We found that the comparison between the calculated percentage of C3 cleavage for each optional postmortem interval and the measured percentage of up to 10% in cadaveric blood leads to the estimation of PMI. This approach is one step towards the development of an accurate method for determining PMI based on C3 cleavage, that is, on a first-order reaction.     

Bullet Trajectory after Impact on Laminated Particle Board

When reconstructing a bullet's trajectory prior to impact using the spatial orientation between two consecutive bullet defects (e.g., by probing), it is important to take the bullet's deflection into account. The (critical) ricochet angles as well as the vertical and horizontal deflection angles of eight cartridge types on laminated particle board have been studied. For all eight of the cartridge types combined, the critical ricochet angles lie between approximately 14° and 26°, while for the subgroup of the jacketed bullets, this range lies lower, between approximately 14° and 18°. The data from this study can be used to assess the accuracy and precision of the applied method. The results show that the highest deflection angles are seen near the critical ricochet angle. Generally speaking, vertical and horizontal deflection angles can almost be neglected above angles of incidence of 30° or 40° for handgun ammunition when shooting at laminated particle board.     

Inflammation in the lungs of infants dying suddenly. A comparative study from two countries

An investigation of lung tissue samples from sudden unexpected infant deaths from the German Democratic Republic (G.D.R.) (n = 106) and Finland (n = 94) shows the German material to contain 54 cases (51%) with advanced inflammatory changes allowing a definite pathologico-anatomical diagnosis and explanation for the death, whereas there were only 19 such cases (20%) in the Finnish material. Slight changes indicating an inflammatory process but not allowing a definite diagnosis ("borderline cases") were seen in one fifth of the cases in both countries. Thus a greater proportion of the child deaths below the age of 1 year in Finland are real cot deaths than in the G.D.R. where signs of respiratory infection can be found more often.     

Influence of CYP2D6 genotype on the disposition of the enantiomers of venlafaxine and its major metabolites in postmortem femoral blood

Venlafaxine (VEN) is an antidepressant drug mainly metabolized by the cytochrome P450 (CYP) enzyme CYP2D6 to the active metabolite O-desmethylvenlafaxine (ODV). VEN is also metabolized to N-desmetylvenlafaxine (NDV) via CYP3A4. ODV and NDV are further metabolized to N,O-didesmethylvenlafaxine (DDV). VEN is a racemic mixture of the S- and R-enantiomers and these have in vitro displayed different degrees of serotonin and noradrenaline reuptake inhibition. The aim of the study was to investigate if an enantioselective analysis of VEN and its metabolites, in combination with genotyping for CYP2D6, could assist in the interpretation of forensic toxicological results in cases with different causes of deaths. Concentrations of the enantiomers of VEN and metabolites were determined in femoral blood obtained from 56 autopsy cases with different causes of death. The drug analysis was done by liquid chromatography tandem mass spectrometry (LC/MS/MS) and the CYP2D6 genotyping by PCR and pyrosequencing. The mean (median) enantiomeric S/R ratios of VEN, ODV, NDV and DDV were 0.99 (0.91), 2.17 (0.93), 0.92 (0.86) and 1.08 (1.03), respectively. However, a substantial variation in the relationship between the S- and R-enantiomers of VEN and metabolites was evident (S/R ratios ranging from 0.23 to 17.6). In six cases, a low S/R VEN ratio (mean 0.5) was associated with a high S/R ODV ratio (mean 11.9). Genotyping showed that these individuals carried two inactive CYP2D6 genes indicating a poor metabolizer phenotype. From these data we conclude that enantioselective analysis of VEN and ODV can predict if a person is a poor metabolizer genotype/phenotype for CYP2D6. Knowledge of the relationship between the S- and R-enantiomers of this antidepressant drug and its active metabolite is also important since the enantiomers display different pharmacodynamic profiles.     

Compstat in Australia: An analysis of the spatial and temporal impact

One of the major trends in policing sweeping across democratic societies since the mid-1990s is a management approach commonly known as COMPSTAT. Despite widespread global adoption, empirical evaluation of the impact of COMPSTAT lags behind popular accounts of its crime control benefits.

Purpose

This article evaluates the crime control impact of Queensland Police Service's version of COMPSTAT known as “Operational Performance Reviews” (OPRs).

Method

A mixed model analytic approach was used to assess the role of OPRs in explaining spatial and temporal variations in crime patterns across Queensland's 29 police districts.

Results

Analysis of the impact of OPRs on reported crime (specifically assaults, robberies and unlawful entries) suggests major differences between police districts, and that some districts are driving overall statewide crime reductions, whilst others confound positive effects of implementation of OPRs in Queensland.

Conclusions

The results demonstrate that the crime drop experienced throughout Queensland found in prior research (Mazerolle et al., 2007) is most likely attributable to a small number of police districts. The implication of these findings is that a number of districts could (and should) be called-upon during maturation of Queensland's OPRs to reduce specific crime problems in their districts and facilitate ongoing crime reductions across the state.