Video Evidence Research Articles

Do wolves ambush beavers? Video evidence for higher‐order hunting strategies

AbstractOver the past decade, there has been much debating about whether wolves possess high‐order cognitive abilities that facilitate deliberate or cooperative hunting strategies such as ambush to capture prey. Beavers can be important alternate or primary prey for wolves in North America and Europe, but no observations of wolves hunting and killing beavers exist. We describe the first documented observation of a gray wolf killing a beaver, an observation that has provided valuable insight into how beavers defend themselves when attacked by wolves, how wolves hunt beavers, and the predatory strategies and cognitive abilities of wolves. Our observation confirms that wolves do hunt and kill beavers by surprising and ambushing them, which demonstrates that wolves have a unique ability to switch between cursorial and ambush hunting strategies depending on the prey. We suggest that wolves learn how to hunt beavers using high‐order mental abilities combined with information learned from prior interactions with beavers.

In the eyes of the law: Perception versus reality in appraisals of video evidence.

In the eyes of the law: Perception versus reality in appraisals of video evidence.

Confirmation of diving and swimming behavior in the Sora (Porzana carolina)

ABSTRACT We first observed Sora (Porzana carolina) swimming and diving under water while capturing them with hand nets at night. Since that time, we have observed the behavior several times and documented it with photos and video. Rails are among the most elusive birds. Despite living in wetlands, water depth has often been discussed as a factor limiting habitat use by rails, with the assumption that when water levels are too deep, rails walk on top of floating or emergent vegetation. Here we present new photo and video evidence that confirms previous observations that Sora are adept at swimming and diving in deep water wetland environments, which should alter how we think about their ability to avoid predators and use deeper water habitats.

Do You See What I See? Problems with Juror Bias in Viewing Body-Camera Video Evidence

In the wake of the Michael Brown shooting in Ferguson, Missouri, advocates and activists called for greater oversight and accountability for police. One of the measures called for and adopted in many jurisdictions was the implementation of body cameras in police departments. Many treated this implementation as a sign of change that police officers would be held accountable for the violence they perpetrate. This Note argues that although body-camera footage may be useful as one form of evidence in cases of police violence, lawyers and judges should be extremely careful about how it is presented to the jury. Namely, the jury should be made aware of their own implicit biases and of the limited nature of the footage. Taking a look at the biases that all jurors hold as well as the inherent subjectivity of video footage, this Note shows how implicit biases and the myth of video objectivity can create problems in viewing body-camera footage and the footage should, therefore, be treated carefully when introduced at trial.

Differences between worker pairs in manual assembly: a case study

Working in pairs is common and often necessary to carry out industrial manual assembly tasks. This paper studies differences in performance that can occur between pairs of workers. Within a case assembly product, activity analysis for each worker in a total of ten pairs and up to four repetitions (learning) is conducted on the basis of video evidence. The results show significant variation in assembly time between the pairs. Repetitions reduce the relative variation, while the ranking of the pairs remains mostly unchanged. In general, the time used for installing parts explain most of the variation between the pairs.

Can tackle height influence tackle gainline success outcomes in elite level rugby union?

In rugby union, effective defensive play is highly technical and essential for game outcomes. Therefore, the aim of this study was to identify tackle heights, for given tackle types, that had a greater propensity to result in tackle gainline success for the tackler using match video evidence. The results indicated that tackling the upper legs of the ball carrier had a greater propensity to result in tackler success for both front-on (OR = 3.27; 95% CI = 1.34–7.95; p < 0.01) and side-on (OR = 5.31; 95% CI = 2.08–13.6; p < 0.01) arm tackles. For shoulder tackles, tackling at the lower trunk for front-on tackles (OR = 1.70; 95% CI = 1.04-2.79; p = 0.03) and the mid trunk for side-on tackles (OR = 3.11; 95% CI = 1.31–7.37; p < 0.01) had a greater propensity to result in tackler success. For smother tackles, tackling at the mid trunk had a greater propensity to result in tackler success during front-on (OR = 3.49; 95% CI = 1.81–6.74; p < 0.01) and side-on (OR = 5.11; 95% CI = 2.42–10.8; p < 0.01) tackles. The results highlight the importance of tackle height when coaching the tackle. The findings also suggest that technically proficient players can advance to more challenging contact techniques than aiming for the ball carrier’s centre of gravity.

Lawsuits & Rulings

Sexual Assault: Graphic video evidence renders due process objections moot Negligence: University has no duty to protect dorm resident from physical assault Campus Security: Knowledge of previous incidents keeps chief on the hook

The Vulnerable fishing cat Prionailurus viverrinus and other globally threatened species in Cambodia's coastal mangroves

AbstractThe Vulnerable fishing cat Prionailurus viverrinus faces a perilous future in South-east Asia. It was last sighted in Cambodia in 2003. We deployed 16 camera traps at four sites in southern Cambodia during January–May 2015 to determine if the fishing cat was still present in the country. Eight photograph/video captures of fishing cats were recorded from the mangroves in Peam Krasop Wildlife Sanctuary and one from Ream National Park, but there were no records from Botum Sakor National Park or Prey Nup. A number of other globally threatened species were also photographed in Peam Krasop Wildlife Sanctuary: the Sunda pangolin Manis javanica, the hog deer Axis porcinus and the large-spotted civet Viverra megaspila. We learnt of the killing of an alleged fishing cat at the Sanctuary in July 2015 in retaliation for raiding fishing nets. Illegal hunting and capture of fishing cats for the wildlife trade were reported by local informants at all sites. We provide photographic and video evidence of the fishing cats and highlight the importance of Cambodia's mangroves for threatened species conservation.

The Documentary Method of [Video] Interpretation: A Paradoxical Verdict in a Police-Involved Shooting and Its Consequences for Understanding Crime on Camera

On July 27th, 2013, Sammy Yatim was shot and killed by Toronto Police Services’ Constable James Forcillo during a verbal confrontation on a streetcar as Yatim brandished a switchblade knife. Forcillo was charged, initially with second degree murder, and later attempted murder—a decision that confused media commentators as attempted murder is a lesser-and-included offense to second degree murder in Canadian law. In January 2016, Forcillo was found not guilty of second degree murder and guilty of attempted murder. Video evidence, recovered from the streetcar’s onboard security cameras, was described by the presiding judge, Justice Edward Then, as proving beyond a reasonable doubt that Forcillo’s testimony was unreliable, especially in light of other evidence. This paper examines the use of video evidence to arrive at a ‘compromise verdict’ (Gillis in ‘Compromise’ verdict in James Forcillo trial gets mixed reaction. Toronto Star, 25 January, 2016) and the paradox of being convicted of attempting to murder someone who was killed.

Detection and localization of copy-paste forgeries in digital videos

Amidst the continual march of technology, we find ourselves relying on digital videos to proffer visual evidence in several highly sensitive areas such as journalism, politics, civil and criminal litigation, and military and intelligence operations. However, despite being an indispensable source of information with high evidentiary value, digital videos are also extremely vulnerable to conscious manipulations. Therefore, in a situation where dependence on video evidence is unavoidable, it becomes crucial to authenticate the contents of this evidence before accepting them as an accurate depiction of reality.Digital videos can suffer from several kinds of manipulations, but perhaps, one of the most consequential forgeries is copy-paste forgery, which involves insertion/removal of objects into/from video frames. Copy-paste forgeries alter the information presented by the video scene, which has a direct effect on our basic understanding of what that scene represents, and so, from a forensic standpoint, the challenge of detecting such forgeries is especially significant. In this paper, we propose a sensor pattern noise based copy-paste detection scheme, which is an improved and forensically stronger version of an existing noise-residue based technique. We also study a demosaicing artifact based image forensic scheme to estimate the extent of its viability in the domain of video forensics. Furthermore, we suggest a simplistic clustering technique for the detection of copy-paste forgeries, and determine if it possess the capabilities desired of a viable and efficacious video forensic scheme. Finally, we validate these schemes on a set of realistically tampered MJPEG, MPEG-2, MPEG-4, and H.264/AVC encoded videos in a diverse experimental set-up by varying the strength of post-production re-compressions and transcodings, bitrates, and sizes of the tampered regions. Such an experimental set-up is representative of a neutral testing platform and simulates a real-world forgery scenario where the forensic investigator has no control over any of the variable parameters of the tampering process. When tested in such an experimental set-up, the four forensic schemes achieved varying levels of detection accuracies and exhibited different scopes of applicabilities. For videos compressed using QFs in the range 70–100, the existing noise residue based technique generated average detection accuracy in the range 64.5%–82.0%, while the proposed sensor pattern noise based scheme generated average accuracy in the range 89.9%–98.7%. For the aforementioned range of QFs, average accuracy rates achieved by the suggested clustering technique and the demosaicing artifact based approach were in the range 79.1%–90.1% and 83.2%–93.3%, respectively.

Graphic video evidence renders due process objections moot

Case name: Plummer, et al. v. University of Houston, et al., No. 15‐20350 (5th Cir. 06/23/17).

Video and clinical screening of national rugby league players suspected of sustaining concussion

ABSTRACTPrimary Objective: This study reviewed the available sideline Sport Concussion Assessment Tool-Third Edition (SCAT3) performance of players who were removed from play using the ‘concussion interchange rule’ (CIR), the available video footage of these incidences, and associated return to play and concussion diagnosis decisions. Research Design: Descriptive, observational case series. Methods and Procedures: Data were collected from all NRL players who used the CIR during the 2014 season. Main Outcomes and Results: Complete SCAT3 and video analysis data were available for 38 (23%) of 167 uses of the concussion interchange rule, of which 20 (52.6%) players were medically diagnosed with concussion. Those with video evidence of unresponsiveness performed more poorly on the modified Balance Error Scoring System (M-BESS; p = .04; Cohen’s d = .69) and reported greater symptoms (p = .03; d = .51). Similarly, players with a vacant stare reported greater symptoms (p = .05; d = .78). Those who demonstrated three signs (unresponsiveness, vacant stare and gait ataxia) performed more poorly on the M-BESS (p = .03; d = 1.4) and reported greater symptoms than those with no observable signs (p = .03; d = 1.4). Conclusions: The SCAT3 is sensitive to the acute effects of concussion in professional athletes; however, a minority of injured athletes might go undetected by this test.

Evidence of Barred Owls (Strix varia) Depredating Nests of Barn Swallows (Hirundo rustica)

From 2010–2012, I studied nesting success and causes of nest failure at a colony of Barn Swallows (Hirundo rustica) where anecdotal evidence suggested the colony was declining in size. In 2010, many nests were destroyed, and indirect evidence suggested breeding adults were being depredated by a raptor. Using trail cameras, I captured video evidence of Barred Owls (Strix varia) depredating two nests, one containing chicks and the other eggs. During the study period, 72% (32/44; 2010), 51% (16/31; 2011), and 85% (17/20; 2012) of nests were depredated, and the number of nesting attempts declined by more than 50% over 3 years. The video evidence and plucked adult feathers suggests that Barred Owls were responsible for at least some of the predation. Barred Owls did not breed historically on the southern British Columbia coast but first appeared in 1966 and have become common breeders, while Barn Swallows have decreased in the same region by 5.64% per year since 1970. There may be many causes of local and regional population declines of Barn Swallows, but given their conspicuous nests, predation in less well protected nesting sites may be a localized cause of colony decline.

Media Exposé of Judicial Corruption in Ghana: Ethical and Theological Perspectives

Article 162, subsection 5, of the 1992 Constitution of Ghana states that “all agencies of the mass media shall, at all times, be free to uphold the principles, provisions and objectives of this constitution, and shall uphold the responsibility and accountability of the Government to the people of Ghana”. Using this constitutional provision that gives the media the power to serve as one of the agents to ensure accountability, this article discusses the media expose of judicial corruption in Ghana by using the recent video evidence of the investigative journalist, Anas. The article considers issues of judicial corruption, the causes, consequences as well as their ethical and theological dimensions. It posits that those who pervert justice through corrupt practices, will eventually be named and shamed. The article concludes that when the media play their role by respecting high journalistic standards, the cause of justice will be served.

Reinventing the allegory of the cave through drama: teachers' challenges and competences in education

This paper focuses the challenges teachers face and the pedagogical – including the relational – competences they develop in dealing with diversity and vulnerability in the construction of a play in the second chance school Escola de Segunda Oportunidade Matosinhos, in Portugal. This arts-based experience provides opportunity to theorise early school leaving (ESL) and educational failure as well as the promotion of inclusive practices as conditions for educational justice. The main questions are: what competences do teachers need in their work to respond to the educational and social needs of vulnerable young people who left education early?; how can teachers’ pedagogical competences be developed in their daily practice?; and how do they feel by doing so?. With these concerns, the paper draws on the video analysis of the construction of the play and on a set of interviews with teachers. Drama is included as part of the syllabus and a strategy to support young adults’ emotional states and will to stay in school. Insights from video evidence include critical commentary on common strategies to promote students’ engagement and learning and the identification of essential competences to deal with it.

The effect of technique on tackle gainline success outcomes in elite level rugby union

Tackling is a major component of rugby union and effective attacking and defensive play are essential for game outcomes. In this study, a number of pre-contact, contact and post-contact tackle characteristics that had an influence on tackle gainline success for the ball carrier and tackler were identified using match video evidence from European Rugby Champions Cup games. A total of 122 front-on tackles and 111 side-on tackles were analysed. For each ball carrier and tackler characteristic, the Odds Ratio and 95% Confidence Interval were calculated based on a gainline success outcome. A Chi-Square and Phi and Cramer’s V calculation was also conducted. A Chi-Square test then identified any statistically significant differences (p < 0.05) for proficiency characteristics between playing position. For both the ball carrier and tackler, tackle characteristics that were indicative of strong and powerful tackle technique such as ‘explosiveness on contact’ and ‘leg drive on contact’ were effective for achieving the desired gainline outcome. Playing position had an influence on only two proficiency characteristics that were statistically significant for gainline success: ‘fending into contact’ for ball carriers and ‘straight back, centre of gravity forward of support base’ for tacklers.

A passive forensic method for video: Exposing dynamic object removal and frame duplication in the digital video using sensor noise features

The purpose of this paper is to detect tampering in the video using passive forensic method. With the extensive availability of sophisticated video editing software and tools, it has become easy to forge the video using different tampering techniques. A well-known video tampering technique is to du plicate the frames or manipulate the contents of the frames to remove and hide the objects or person in a video. Video forensic is necessary because people tampered the video to get justice from court of law on the basis of video evidence, disgrace the important celebrity and to hide or expose some unwanted object. In this paper, we propose a passive forensic method to expose dynamic object removal and frames duplication by detecting the noise variance between original and tampered video frames. The proposed method exploits sensor noise features, extracted from each frame of the video using Discrete Wavelet Transform (DWT) and nonlinear thresholding such as Hard and Soft with Stein’s Unbiased Risk Estimator (SURE) shrinkage. Gaussian Mixture Density (GMD) is used as Bayesian classifier and Expectation-Maximization (EM) algorithm set the parameters of the GMD. Implementation results demonstrate that we are getting commendable processing speed, accuracy 97.36-96.26%, recall 99.80-98.94% and precision 97.34-87.95% respectively for object removal and frame duplication detection in comparison to existing methods. Proposed method successfully detect and localize forgery in the given video.

The implications of gas slug ascent in a stratified magma for acoustic and ground deformation source mechanisms in Strombolian eruptions

The interpretation of geophysical measurements at active volcanoes is vital for hazard assessment and for understanding fundamental processes such as magma degassing. For Strombolian activity, interpretations are currently underpinned by first-order fluid dynamic models which give relatively straightforward relationships between geophysical signals and gas and magma flow. However, recent petrological and high-speed video evidence has indicated the importance of rheological stratification within the conduit and, here, we show that under these conditions, the straightforward relationships break down. Using laboratory analogue experiments to represent a rheologically-stratified conduit we characterise the distinct variations in the shear stress exerted on the upper sections of the flow tube and in the gas pressures measured above the liquid surface, during different degassing flow configurations. These signals, generated by varying styles of gas ascent, expansion and burst, can reflect field infrasonic measurements and ground motion proximal to a vent. The shear stress signals exhibit timescales and trends in qualitative agreement with the near-vent inflation–deflation cycles identified at Stromboli. Therefore, shear stress along the uppermost conduit may represent a plausible source of near-vent tilt, and conduit shear contributions should be considered in the interpretation of ground deformation, which is usually attributed to pressure sources only. The same range of flow processes can produce different experimental infrasonic waveforms, even for similar masses of gas escape. The experimental data resembled infrasonic waveforms acquired from different vents at Stromboli associated with different eruptive styles. Accurate interpretation of near-vent ground deformation, infrasonic signal and eruptive style therefore requires detailed understanding of: a) spatiotemporal magma rheology in the shallow conduit, and b) shallow conduit geometry, as well as bubble overpressure and volume.

Predation by invasive signal crayfish on early life stages of European barbel may be limited

Abstract To determine whether or not signal crayfish Pacifastacus leniusculus and native white‐clawed crayfish Austropotamobius pallipes prey on European barbel Barbus barbus eggs, interstitial free‐embryos and emergent larvae, experiments were undertaken in salmonid (substratum) incubators (six treatments, four controls) fitted with video recorders. No corpses or remains of emergent barbel larvae or eggs, or parts thereof, were observed in any of the incubators containing buried eggs, and no emergent larvae showed any sign of attack. However, video evidence of a signal crayfish catching and consuming a barbel larva was obtained. There were no statistically significant differences between white‐clawed and signal crayfish either in carapace length or weight at the beginning and end of the experiments. The conservation implications of these results are discussed.

Forensic Diagnostics of the Circumstances of Digital Video and Audio Production: Analytical Review

The analytical review examines the issues of forensic investigation into the circumstances of production of digital video and audio recordings. The paper presents the organization and lines of inquiry in forensic analysis of video and audio evidence, computer forensics, forensic linguistics, and psychological evaluation established in the system of forensic science organizations of the Russian Ministry of Justice by 2013–2016. The analysis covers the issues of independent or integrated application of the listed types of special knowledge in order to meet the discipline-specific and comprehensive objectives of determining the circumstances of video/audio production. General strategies and types of forensic diagnostics of production circumstances are discussed without too much emphasis on the methodological minutiae of every stage of the investigation.