Officers’ memory and stress in virtual lethal force scenarios: Implications for policy and training

ABSTRACT

Sworn law enforcement officers (N?=?151) were exposed to two different simulated lethal force encounters, a motorcycle-traffic-stop (MTS) and a workplace violence incident. Workplace violence incidents (WPV) consisted of two versions: an original version (WVO) and an enhanced version (WVE) with additional tactile and auditory stimuli within the simulation environment. Officers’ recognition memory (immediate and 48?h later), perceived stress, and physiological stress responses were examined. Delayed reporting led to impaired memory for event information in the MTS and perpetrator information in the WVE simulation. Moreover, perpetrator information was remembered more accurately than event information. Two physiological stress markers – alpha amylase and immunoglobulin-a – were correlated with memory for the simulated experiences; however, cortisol and interleukin-6 were not. These findings support current theory related to arousal and memory suggesting that officers should be interviewed as soon as reasonably possible after a lethal force incident. Implications for legal parameters in defining a ‘reasonable officer’ exerting lethal force are considered.     

An analysis of police officers' decisions about whether to refer cases of child abuse for prosecution

Facial composite research has mainly focused on their investigative value. No. comparable attention was drawn to their probative value – the extent to which a composite image may serve as incriminating or exonerating evidence against a defendant. The existing data resulting from mock-juror research allow only cautious conclusions and applies solely to the common law system. Therefore an experiment was conducted involving laypeople (N = 74) and prosecutor apprentices (N = 72). All participants received case materials of a robbery committed by a young male, including the victim's and defendant's testimonies and other evidence. In both samples, the facial composite evidence was manipulated so that participants viewed a composite image that was either a good or a poor match to the defendant. A facial composite that bore a strong resemblance to the defendant influenced the assessment of the eyewitness' credibility in the apprentices sample, but failed to affect other dependent variables. Surprisingly, laypeople ignored the facial composite no matter how well it resembled the defendant. Significant differences in the assessment of eyewitness' credibility, the strength of the defense case, the credibility of the defendant's alibi, and his culpability were found between the prosecutor apprentices and laypeople. The practical implications of these findings are discussed.     

Gunshot residue testing in suicides: Part I: Analysis by scanning electron microscopy with energy-dispersive X-ray

Several different methods can be employed to test for gunshot residue (GSR) on a deceased person's hands, including scanning electron microscopy with energy-dispersive x-ray spectroscopy (SEM-EDX) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). Each of these techniques has been extensively studied, especially on living individuals. The current studies (Part I and Part II) were designed to compare the use and utility of the different GSR testing techniques in a medical examiner setting. In Part I, the hands of deceased persons who died from undisputed suicidal handgun wounds were tested for GSR by SEM-EDX over a 4-year period. A total of 116 cases were studied and analyzed for caliber of weapon, proximity of wound, and results of GSR testing, including spatial deposition upon the hands. It was found that in only 50% of cases with a known self-inflicted gunshot wound was SEM-EDX positive for at least 1 specific particle for GSR. In 18% of the cases there was a discernible pattern (spatial distribution) of the particles on the hand such that the manner in which the weapon was held could be determined. Since only 50% of cases where the person is known to have fired a weapon immediately prior to death were positive for GSR by SEM-EDX, this test should not be relied upon to determine whether a deceased individual has discharged a firearm. Furthermore, in only 18% of cases was a discernible pattern present indicating how the firearm was held. The low sensitivity, along with the low percentage of cases with a discernible pattern, limits the usefulness of GSR test results by SEM-EDX in differentiating self-inflicted from non-self-inflicted wounds.