Estimation of legal age using calcification stages of third molars in living individuals

The increased number of adolescents and young adults with unknown or inaccurately given date of birth is a current issue in justice and legal medicine. The objective of this study was to determine the extent to which third molar calcification stages assessed on panoramic X-rays could be useful as additional criteria for forensic age estimation in living individuals, focusing on the legally important ages 17 and 18.In a retrospective multi-center study, the developmental stage of each individual's third molar was analyzed using Demirjian's scale in 2360 cases. Additionally, sex, age and ancestry were assessed.Individuals with the lowest calcification stage of all present molars in stage H were ≥ 18 years with a likelihood of ≥ 99.05% in the female (n = 388), and ≥ 99.24% in the male (n = 482) population.The lowest calcification stage of all present third molars proved to be useful as an additional reliable criterion for the determination of an age ≥ 18 years.     

Age estimation by pulp/tooth area ratio in canines: Cameriere's method assessed in an Indian sample using radiovisiography

Age estimation of an individual whether living or dead is an intimidating task in forensic investigations. Since teeth are more resistant to most peri- and post-mortem changes, they are frequently used for identification and age estimation when skeletal remains are in poor condition. However, most methods are destructive and warrant extraction of teeth which is not feasible in living individuals. Cameriere's et al. put forth a radiographic method of age estimation by pulp to tooth area ratio (AR) in canines and revealed a linear regression between age and the AR. In the present study, we estimated the AR in 456 canines (upper, lower and both) in an Indian sample (114 males and 114 females) using radiovisiography technique. Linear regression equations were derived for upper canine, lower canine and both using the AR to estimate chronological age. Additionally, the efficacy of these equations was also evaluated in younger age group (<45 years). The formulas derived, i.e., age = 96.795 ? 513.561x₁ (Eq. (1)) for upper canine, age = 88.308 ? 458.137x₂ (Eq. (2)) for lower canine and age = 99.190 ? 283.537x₁ ? 306.902x₂ + 400.873x₁x₂ (Eq. (3)) for both the canines were applied to predict the chronological age. The mean value of residuals using these regression equations ranged from 4.28 to 6.39 years with upper canine equation generally giving a precise result. When these equations were applied for younger ages (<45 years), the regression equation derived from both canines gave a better result (mean residual 2.70 years). Overall these equations were better able to predict the age in younger ages, i.e., up to 45 years.     

Determination of amphetamine-type stimulants,ketamine and metabolites in fingernails by gas chromatography–mass spectrometry

A gas chromatography–mass spectrometry (GC–MS) method was developed and validated for the simultaneous qualification and quantification of methamphetamine (MA), amphetamine (AP), 3,4-methylenedioxy-N-methylamphetamine (MDMA), 3,4-methylenedioxy-N-amphetamine (MDA), ketamine (KET) and norketamine (NKT) in fingernails. Fingernail samples (20 mg) were washed with distilled water and methanol, digested with 1.0 M sodium hydroxide at 95 °C for 30 min, and then extracted with ethyl acetate. Extract solutions were evaporated to dryness, derivatized using heptafluorobutyric anhydride (HFBA) at 60 °C for 30 min, and analyzed by GC–MS. The linear ranges were 0.1–20.0 ng/mg for AP, MDMA and NKT, 0.2–20.0 ng/mg for MA and MDA, and 0.4–20.0 ng/mg for KET, with the coefficients of determination (r² ≥ 0.9989). The intra- and inter-day precisions were within 7.1% and 10.6%, respectively. The intra- and inter-day accuracies were ?10.9% to 0.8% and ?4.3% to 4.5%, respectively. The limits of detections (LODs) and the limits of quantifications (LOQs) for each analyte were lower than 0.094 ng/mg and 0.314 ng/mg, respectively. The recoveries were in the range of 72.3–94.9%. The average fingernail growth rates of two subjects for three years and six subjects for two months were 3.12 mm/month and 3.16 mm/month, respectively. The method proved to be suitable also for the simultaneous detection and quantification of MA, MDMA, KET and their metabolites in fingernails.     

Comparison of the three age estimation methods: Which is more reliable for Turkish children?

BackgroundThree atlases—the GÖK, the Greulich–Pyle (GP), and the Tanner–Whitehouse (TW3)—are used frequently for age determination in Turkey. The purpose of this study was to evaluate the applicability of these three methods related to the skeletal age assessment for Turkish adolescents.Materials and methodsThe conventional roentgenograms of the left hands and wrists, elbows, shoulders, and pelvises of 333 healthy Caucasian children (164 females, 169 males) who fit the study and the criteria of each atlas were obtained. The mean differences (± standard deviation [S.D.] in years) between the chronologic age (CA) and the skeletal age (BA), which were obtained by using each age estimation method, were calculated and tested using t-test.ResultsFor girls, the most accurate method was the TW3 (mean differences (d): ?0.21 (p < 0.05)), following by the GP (d: 0.66 (p < 0.001), and the GÖK (d: 2.99 (p < 0.001)). For boys, the most accurate method was the GP (d: ?0.02 (p > 0.05)), followed by the TW3 (d: ?0.18 (p < 0.05)) and GÖK (d: 1.05 (p < 0.001)).Discussion and conclusionsResults show that the TW3 (for girls) and the GP (for boys) methods are more appropriate than the GÖK atlas for estimating the BA. GÖK could be used for boys aged 11–14 years but it should not be used for girls.     

Effects of advanced age and dementia on restoration of competence to stand trial

Elderly defendants (age 65+) and defendants with dementia adjudicated incompetent to stand trial and hospitalized for restoration to competence (RTC) often present unique challenges to clinicians charged with their restoration. In this study, we attempted to better identify predictors of successful RTC by building upon previous research correlating increased age with decreased likelihood of RTC. We identified elderly non-demented defendants (n = 31) and defendants diagnosed with dementia (n = 47) from a state database of 1380 individuals hospitalized for competence restoration from 1988–2004. Using regression analysis and correcting for demographic variables and common admission psychiatric diagnoses, we studied the relationship of age at hospital admission and dementia diagnosis on the likelihood of successful RTC. Both advanced age and dementia diagnosis were associated with decreased RTC. After correcting for dementia diagnosis, increased age retained its negative correlation with restoration success. Both elderly non-demented defendants and defendants diagnosed with dementia were significantly less likely to be restored to competence than all other RTC admissions (n = 1302). However, a substantial percentage of both demented and elderly non-demented defendants were successfully restored to competence, potentially justifying restoration attempts for both of these groups of defendants.     

Forensic oral imaging quality of hand-held dental X-ray devices: Comparison of two image receptors and two devices

Recently, different portable hand-held and battery-powered dental X-ray units have become available. Especially for forensic odontological purposes, they offer diverse advantages such as for use in disaster areas and crime-scene locations as also in autopsy rooms and mortuaries. For any application, the most important feature of these hand-held devices is the delivered image quality. The aim of this study is to evaluate the radiographic image quality acquired by two portable X-ray devices in combination with two types of image receptors and to compare the findings with the image quality of a standard intra-oral X-ray device.Eleven samples consisting of eight teeth, two dry skeletal specimens and one formalin-fixed mandible part were mounted on blocks for standardised (re)positioning. Radiological images were acquired with two hand-held (AnyRay^® 60 kVp, 0.02–4.00 mAs and NOMAD^® 60 kVp, 0.023–2.277 mAs) and one wall-mounted (MinRay^® 60/70 kVp 0.14–22.4 mAs) X-ray device combined with two image receptor systems (VistaScan^® phosphor storage plate (PSP) and SIGMA^® M CMOS Active Pixel technology sensor). The effect of X-ray source-to-object distance (SOD) was checked at 20 cm in conjunction with object to image receptor distances (OIDs) of 0.8 and 2.5 cm. For each parameter setup, the exposure times were run from low till high. An expert consent statement was achieved by agreement of four expert observers selecting the optimal images based on a developed four point quality rating system. Next, a selection of the images was assembled in a set of 198 observation screens and scored by seven observers. The observation screens were designed to compare observer scores, relations between devices, receptors and OIDs and images obtained from the different devices at equal exposure levels (mAs). All results were statistically analysed.Radiological image quality was significantly higher for phosphor plate compared with the CMOS digital receptor system (p < 0.0001). Furthermore, a significantly superior image quality was obtained for OID = 0.8 than for OID = 2.5 (p = 0.039). A significant difference in image quality between the three devices was also established (p = 0.02). The present study demonstrated the feasibility of portable X-ray systems for forensic odontological applications based on rendering optimal image quality, provided an in vitro guideline of optimal parameter settings and offered a radiological image database usable in further research.     

The identification of individuals by observational gait analysis using closed circuit television footage

This study investigated the ability of individuals with experience in gait analysis to identify people by observing features of gait recorded by closed circuit television cameras (CCTV). Seven experienced analysts each viewed five samples of footage. Each sample showed a “target walker” and five “suspect walkers.” The task of the experienced analysts was to determine which, if any, of the “suspect walkers” was the “target walker.” All of the participant “walkers” wore identical loose fitting clothing to mask anatomical and body contour features, and balaclavas to obscure facial features. The overall results showed that the experienced analysts made a correct decision in 124 of 175 cases (71%), significantly better than would have been expected to have occurred by chance (p < 0.05). A significant variation in correct decisions (p < 0.05) was shown to occur between the various angles from which the footage was recorded, footage recorded in the saggital plane showing the highest number of correct decisions. Significantly more correct decisions (p < 0.05) were also shown to occur when the footage of the “target walker” and that of the “suspect walker” were taken from the same angle. The results suggest that individuals with experience in gait analysis perform well in the comparative identification of suspects from CCTV footage, and therefore do have a role to play as expert witnesses in this field.     

Multiple murder and criminal careers: A latent class analysis of multiple homicide offenders

PurposeTo construct an empirically rigorous typology of multiple homicide offenders (MHOs).MethodThe current study conducted latent class analysis of the official records of 160 MHOs sampled from eight states to evaluate their criminal careers.ResultsA 3-class solution best fit the data (?2LL = ?1123.61, Bayesian Information Criterion (BIC) = 2648.15, df = 81, L² = 1179.77). Class 1 (n = 64, class assignment probability = .999) was the low-offending group marked by little criminal record and delayed arrest onset. Class 2 (n = 51, class assignment probability = .957) was the severe group that represents the most violent and habitual criminals. Class 3 (n = 45, class assignment probability = .959) was the moderate group whose offending careers were similar to Class 2.ConclusionA sustained criminal career with involvement in versatile forms of crime was observed for two of three classes of MHOs. Linkages to extant typologies and recommendations for additional research that incorporates clinical constructs are proffered.     

Transfer of fibres on the hands of living subjects and their persistence during hand washing

Textile fibres were transferred to the hands of ten living subjects and their persistence was determined after hand washing. Average number of fibres transferred was 300 ± 133 (female 288 ± 92, male 311 ± 163) per 100 cm² hand area in the 100 experiments. However the number of fibres transferred was not gender dependent but individual dependent. The hand texture of subjects was compared with the number of fibres transferred but the relationship was not observed. The number of fibres transferred varied significantly for the 10 repeated experiments performed under the same conditions for the same subject.The subjects were then asked to wash their hands with water. One test group washed their hands with standing water, and the other with running tap water. Afterwards, the number of fibres remaining on the test subjects' hands were investigated. Migration of the fibres on the surface of the observed hands did occur but total loss of transferred fibre after hand washing did not occur. The average number of fibres remaining per 100 cm² hand area was 14 ± 10 (range = 3–72) for hand washing with standing water, and 10 ± 12 (range = 0–79) for washing with running tap water. The results of this study show the possibility of finding fibres on the hands of a person involved in a criminal case even after hand washing before fibre collection.     

Validity of Demirjian and Willems methods for dental age estimation for Malaysian children aged 5–15 years old

BackgroundOne of the most commonly used method for dental age assessment is the method reported by Demirjian and coworkers in 1973. It was later modified by Willems and coworkers whereby they &ldquo;performed a weighted ANOVA&rdquo; in order to adapt the scoring system.AimTo evaluate the applicability of Demirjian and Willems methods for dental age estimation for Malaysian children and to correlate the accuracy of the findings with the chronology of tooth development of premolars and second molars.Materials and methodsA total of 991 dental panoramic radiographs of 5–15-year-old Malaysian children were included in the study. The mean Demirjian and Willems estimated ages were compared to the mean chronological age.ResultsThe mean chronological age of the sample was 10.1 ± 2.8 and 9.9 ± 3.0 years for males and females respectively. Using the Demirjian method, the mean estimated dental age was 10.8 ± 2.9 years for males and 10.5 ± 2.9 years for females. For Willems method, the mean estimated age was 10.3 ± 2.8 years males and 10.0 ± 3.0 years respectively.ConclusionsWillems method was more applicable for estimating dental age for Malaysian children. Overestimation in Demirjian method could be due to advanced development of second bicuspids and molars.     

The Successful Onset of Sex Offending: Determining the Correlates of Actual and Official Onset of Sex Offending

PurposeThe current study investigates the covariates of age of onset (actual and official) and cost avoidance of sex offending in first-time convicted sex offenders.MethodsThe current study utilized a large sample (n = 332) of federally sentenced first-time convicted adult male sex offenders. Actual onset was measured using self-report, victim statements, and police investigation notes. Official onset was measured using age at first conviction. Cost avoidance was measured as the time gap between actual and official onset.ResultsFirst, while most offenders initiated their sexual criminal career in their early adult years (25–35 years) they were typically not arrested until middle adulthood. Second, the covariates for official onset are in line with cost avoidance, but not actual onset. Third, offenders best able to avoid costs were early starters with a conventional background (i.e., employed, absence of a conviction for a non-sex crime), targeting prepubescent children within the family context.ConclusionsWhile early actual onset offenders were more likely to target stranger victims, early official starters exhibited an unconventional background, prior criminal record, more extensive sexual criminal career, and targeted strangers. Thus, official, but not actual onset revealed a profile in line with prior research.     

Detection of acute fentanyl exposure in fresh and decomposed skeletal tissues part II: The effect of dose–death interval

The effects of dose–death interval on the detection of acute fentanyl exposure in fresh and decomposed skeletal tissues (marrow and bone), by automated enzyme-linked immunosorbent assay (ELISA) are described. Rats (n = 14) were administered fentanyl acutely at a dose of 0 (n = 2) or 60 μg/kg (n = 12) by intraperitoneal injection, and euthanized within 20, 45, 135, or 225 min. Femora and tibiae were extracted from the fresh corpses and marrow was isolated from the femoral and tibial medullary cavities. The remains were then allowed to decompose outdoors to the point of complete skeletonization, and vertebrae, pelvi and miscellaneous (humeri and scapulae) were recovered for analysis. In all cases, bones were cleaned in alkaline solution and then ground into a fine powder. Marrow was homogenized in alkaline solution. Fentanyl was extracted from ground bone by methanolic extraction. Extracts were adjusted to pH 6 and analyzed by ELISA. Perimortem heart blood was also collected and diluted in phosphate buffer prior to screening by ELISA. The effect of tissue type on ELISA response was examined through determination of binary classification test sensitivity and the relative decrease in absorbance (%DA, drug-positive tissues vs. drug-free controls) in each tissue type. Overall, the %DA varied significantly between extracts from different skeletal tissues at a given dose–death interval, according to the general order of marrow > decomposed bone > fresh bone. Binary classification test sensitivity values for fentanyl in marrow, fresh epiphyseal (femoral and tibial) bone, fresh diaphyseal (femoral and tibial) bone, decomposed vertebrae, decomposed pelvic bone, and decomposed miscellaneous bone were 67–100%, 0–33%, 0–33%, 0–67%, 0–67% and 0–33%, respectively, over all dose–death intervals. Although group mean %DA values showed a strong negative correlation with dose–death interval in marrow, fresh epiphyseal bone, decomposed vertebrae, pelvic and miscellaneous bone (r = ?0.989, ?0.930, ?0.955, ?0.903, and ?0.974, respectively), the high variability in both fresh and decomposed bone precluded differentiation of the dose–death intervals based on %DA value alone. Overall, the results suggested that the type of skeletal tissue sampled may not be as important as the amount of residual marrow remaining in skeletonized remains.     

The age estimation of blood stains up to 30 days old using visible wavelength hyperspectral image analysis and linear discriminant analysis

A novel application of visible wavelength hyperspectral image analysis has been applied to determine the age of blood stains up to 30 days old. Reflectance spectra from selected locations within the hyperspectral image, obtained from a portable instrument, were subjected to spectral pre-processing. This was followed by the application of a linear discriminant classification model, making estimations possible with an average error of ± 0.27 days for the first 7 days and an overall average error of ± 1.17 days up to 30 days. This is also the first reported study of the determination of the age of fresh blood stains (less than one day old) with an error of ± 0.09 h. The studies have been made under controlled conditions and represent, at this stage, proof of concept results but also are the most accurate age estimation results for measurements between 0 and 30 days reported to date. The results are consistent with well-established kinetic processes suggesting that the pre-processing stages described are revealing spectroscopic changes which are reliably following the time dependent oxidation of HbO₂. The potential for parameterisation of environmental factors to make the method generally applicable at crime scenes is discussed, along with the developments required to further improve classification and to make the instrument genuinely portable.     

Prevalence of blood alcohol in fatal traffic crashes in Shanghai

The objective of this project was to investigate the incidence of alcohol consumption in fatal traffic deaths in Shanghai, one of the largest cities in China. A study was conducted on 803 individuals killed in road accidents during the period 2009–2011, in terms of alcohol-positive rate, mean blood alcohol content (BAC), gender, age, vehicle type, pedestrian alcohol problem, single-vehicle vs multiple-vehicle crashes, and time of day. It was found that 28.9% of the drivers involved had a BAC ≥ 0.20 mg/mL (limit of civil offense) and 21.8% had a BAC ≥ 0.80 mg/mL (limit of criminal offense). The mean BAC of alcohol-positive drivers (with a BAC ≥ 0.20 mg/mL) was 1.51 mg/mL. The vast majority of the drivers involved were males. With regards to age, the largest group was of drivers aged between 40 and 49 years group in both alcohol-negative cases (26.8%) and alcohol-positive cases (26.2%). Motorcycles were most likely to be involved, representing 34.4% of alcohol-negative crashes and 51.6% of alcohol-positive crashes. Very high BACs were common among alcohol-positive pedestrians, yet all female pedestrians were alcohol-negative. Single-vehicle crashes were over-represented in alcohol-positive cases. Alcohol-negative crashes and alcohol-positive crashes most often happened during the time period of 17:00–18:59 and 19:00–20:59, respectively.     

Duplex-specific nuclease (DSN): A method for the rehabilitation of low-copy number DNA profiles

A continual challenge in the field of forensic DNA analysis is the amplification and interpretation of degraded and low-copy number (LCN) DNA obtained from amounts of limited biological evidence. It has been well established that DNA profiles obtained from the amplification of low quality, degraded, and/or LCN DNA samples are often of limited value due to the frequent occurrence of preferential amplification during polymerase chain reaction (PCR). The by-products of preferential PCR amplification are often observed as inter- and intra-locus peak imbalance, allelic dropout, and/or locus dropout. These are all artifacts that are identified during the interpretation phase of analysis rather than by improving the quality of the DNA present. While it is theoretically possible to obtain a complete DNA profile from a single cell, in reality, profiles obtained from suboptimal amounts of DNA are difficult to interpret and frequently inconsistent when replicated. Inspired by advances in next-generation sequencing techniques, we propose a methodology for simultaneously normalizing the abundance of PCR products across all short tandem repeat (STR) loci using the DNA exonuclease, duplex-specific nuclease (DSN). DSN is an enzyme isolated from the hepatopancreas of Red King (Kamchatka) crab that possesses a strong affinity for digesting double stranded DNA (dsDNA) and has limited activity toward single stranded DNA (ssDNA). Degraded DNA known to display peak imbalance and allele dropout was amplified using AmpFlSTR^® Identifiler^® Plus for 28 cycles. Following amplification, samples were denatured at 99.9 °C for 5 min and incubated with one unit of DSN at 62 °C in a 28 μl volume for 1 min. Nuclease activity was terminated through the addition of equal volume of 10 mM EDTA and 95 °C incubation for 2 min. Following DSN treatment, 21 of 30 alleles within the known profile exhibited some improvement in peak height balance. The findings obtained support the potential use of DSN treatment as a method for normalizing STR profiles and improving the quality of data from degraded and low quantity DNA samples.     

Analysis of hair after contamination with blood containing cocaine and blood containing benzoylecgonine

In post-mortem work, blood is a potential source of external contamination of hair. The present study was carried out to investigate the amount of drug absorbed into hair which has been contaminated with blood containing either cocaine or BE. Solutions were prepared containing 0.05, 0.1, 0.2, 0.5 and 3.0 μg/mL of either cocaine or BE in human blood. Samples of approximately 3.2 g of drug-free hair were contaminated by soaking in the blood solutions for 5 min. They were then removed and left at room temperature. Approximately 0.5 g of hair was collected from each of the blood soaked hair samples at 6 h, 1, 2, 4 and 7 days after contamination. As each hair sample was collected it was shampoo-washed to prevent further drug absorption. Hair samples were analysed in triplicate using a fully validated method described previously. EME and cocaethylene were also measured in order to find out if cocaine or BE was breaking down to these compounds. Both cocaine and BE were absorbed into hair in significant concentrations when the concentration in the blood was 0.5 μg/mL or greater; cocaine was more readily absorbed than BE. Cocaine broke down to EME (<LOQ) at 0.5 μg/mL and to EME (>LOQ) and BE (<LOQ) at 3.0 μg/mL. When the blood concentration of cocaine was 0.5 μg/mL or less, there was no evidence of it breaking down to form BE. From the samples soaked in blood containing BE, there was no evidence of the BE breaking down. The absorption of drug into hair did not increase as the contamination period increased from 6 h to 7 days.     

Freezing skeletal muscle tissue does not affect its decomposition in soil: Evidence from temporal changes in tissue mass,microbial activity and soil chemistry based on excised samples

The study of decaying organisms and death assemblages is referred to as forensic taphonomy, or more simply the study of graves. This field is dominated by the fields of entomology, anthropology and archaeology. Forensic taphonomy also includes the study of the ecology and chemistry of the burial environment. Studies in forensic taphonomy often require the use of analogues for human cadavers or their component parts. These might include animal cadavers or skeletal muscle tissue. However, sufficient supplies of cadavers or analogues may require periodic freezing of test material prior to experimental inhumation in the soil. This study was carried out to ascertain the effect of freezing on skeletal muscle tissue prior to inhumation and decomposition in a soil environment under controlled laboratory conditions. Changes in soil chemistry were also measured. In order to test the impact of freezing, skeletal muscle tissue (Sus scrofa) was frozen (?20 °C) or refrigerated (4 °C). Portions of skeletal muscle tissue (～1.5 g) were interred in microcosms (72 mm diameter × 120 mm height) containing sieved (2 mm) soil (sand) adjusted to 50% water holding capacity. The experiment had three treatments: control with no skeletal muscle tissue, microcosms containing frozen skeletal muscle tissue and those containing refrigerated tissue. The microcosms were destructively harvested at sequential periods of 2, 4, 6, 8, 12, 16, 23, 30 and 37 days after interment of skeletal muscle tissue. These harvests were replicated 6 times for each treatment. Microbial activity (carbon dioxide respiration) was monitored throughout the experiment. At harvest the skeletal muscle tissue was removed and the detritosphere soil was sampled for chemical analysis. Freezing was found to have no significant impact on decomposition or soil chemistry compared to unfrozen samples in the current study using skeletal muscle tissue. However, the interment of skeletal muscle tissue had a significant impact on the microbial activity (carbon dioxide respiration) and chemistry of the surrounding soil including: pH, electroconductivity, ammonium, nitrate, phosphate and potassium. This is the first laboratory controlled study to measure changes in inorganic chemistry in soil associated with the decomposition of skeletal muscle tissue in combination with microbial activity.     

Expression of fibronectin suicidal in gunshot wounds

Fibronectin has been proposed as the reliable marker of wound vitality and potent tool for age estimation in cases where survival time is at least few minutes. Cases of suicidal gunshot wounds were divided into two groups according to projectile energy and damage of the vital structures. Immunohistochemical reaction on fibronectin was evaluated with semiquantitative scale, which included sum of intensity and widespread of the reaction. Mann–Whitney test has shown statistical significant difference between groups (P ≤ 0.001).     

Perceptions and experiences of people with mental illness regarding their interactions with police

This study examined the perceptions and lived experiences of people with mental illness in relation to their interactions with the police. A community-based participatory research approach was used and a procedural justice theoretical perspective guided the study. In-depth, semi-structured interviews were conducted by peer researchers with 60 people with mental illness who had interacted with the police and were living in Metro Vancouver, Canada. Among the study participants, contact with the police was frequent and occurred under a diverse range of circumstances. The majority of participants perceived being treated in a procedurally just manner by the police officer(s) who were involved in their most recent interaction. Almost three-quarters (n = 43, 72%) of participants were generally satisfied with how the police officer(s) had handled their most recent interaction. The slight majority of participants (n = 30, 51%) rated their previous contacts with the police as a positive experience overall, with 32% (n = 19) indicating that their previous interactions with the police were negative life experiences. The findings paint a more balanced picture than that which is often portrayed by the media. Emphasizing a procedural justice framework for police handling of situations involving people with mental illness is a vital step toward improving how these interactions are experienced and perceived.     

Characterisation of forward stutter in the AmpFlSTR® SGM Plus® PCR

PCR amplification of tetrameric short tandem repeats (STRs) can lead to Taq enzyme slippage and artefact products typically one repeat unit less in size than the parent STR. These back stutter or n ? 4 amplification products are low-level relative to the amplification of the parent STR but are widely seen in the forensic community where tetrameric STRs are employed in the generation of DNA profiles. To aid the interpretation of DNA mixtures where minor contributor(s) might be present in comparable amounts to the back stutter products, the typical amounts of back stutter generated have been well characterised and guidelines for interpretation are in place. However, further artefacts thought to be Taq enzyme slippage leading to products with one repeat unit greater than the parent sequence (n + 4 or forward stutter) or two repeats less (n ? 8 or double back stutter) also occur, but these have not been well characterised despite their potential influence in mixture interpretations. Here we present findings with respect to these additional artefacts from a study of 10,000 alleles and include guidelines for interpretation.