Force Science News #253:

New study: "No fatal risk" in proning out violent resisters

In this issue:


I. A congratulations and a welcome to new FS Instructor Laura Scarry

II. New study: "No fatal risk" in proning out violent resisters

III. New findings on obese subjects & prone positioning

IV. Latest news on OIS that occurred inside an accelerating van

V. FS faculty member trains feds to interview "Persons of Concern"


I. Congratulations to grads and welcome to additional Cert Course instructor


Congratulations to the graduates of the most recent Force Science Certification Course! They proudly represented 34 agencies from 12 states and three countries--including two mates from Queensland Police Service in Australia who shared fascinating insights into law enforcement life in the Down Under. We're honored to add them to the rapidly growing team of Certified Force Science Analysts worldwide. Also, a very big thank you to the Glenview, Illinois Police Department who will be hosting a Certification Course again next month.


Additionally, we're proud to announce that after an extremely successful guest presentation at the last Certification Course, nationally recognized law enforcement attorney, Laura Scarry, has been officially added to our team of Force Science Certification Course instructors. Her block of instruction will be included in all upcoming Force Science Certification Courses beginning with the class scheduled for May 19-23, 2014 in Glenview, IL. Laura, who is also a Cert Course graduate, will combine her outstanding awareness of the complex human factors involved in high-stress, rapidly unfolding force encounters with her nationally renowned legal expertise to bring unique pre- and post-event insights to FS Certification Course students. It's an honor to welcome Laura to the our team!


For information on the Force Science Certification Course and for a list of remaining 2014 locations please click here or visit:



II. New study: "No fatal risk" in proning out violent resisters


In a new, broad-based study of violently resisting suspects, a prominent researcher has found that restraint in the prone position produces no fatal adverse effects, even when Taser shocks, weight on the subject's back, and hobbling are employed by officers to gain control.


"No method of control or restraint used in the field produced a significant level of adverse risk," the researcher, Dr. Darrell Ross, declared in debuting his study findings at the recent annual conference of the International Law Enforcement Educators & Trainers Assn. (ILEETA). "If I had to tell you one thing, it would be to continue to prone out violently resisting people, for both your safety and theirs."


The controversy over prone positioning has raged in the policing community since the 1980s. But Ross, the CJ department head at Valdosta State University in Georgia and a frequent expert witness on police practices, claims criticism of the tactic has largely stemmed from three small studies that he charges were "medically flawed" and based on "assumptions and junk science." These studies alleged a connection between prone positioning and asphyxiation that resulted in sudden in-custody deaths.


At least 15 other studies, of which his is the latest, have concluded that "positional restraint is not associated with injury and death," he says. These studies have found no clinically significant changes in cardio output, heart rate, blood pressure, blood chemistry, or respiratory function caused by prone positioning, even with up to 250 pounds of weight force imposed on the subject, Ross reports.


DATA POOL. Ross's study, titled "Analyzing the Science & the Outcome of Prone Restraint," examines in detail the actual field applications of prone positioning throughout the last calendar year in 18 law enforcement agencies in six states (CA, GA, IL, MI, KS, and MS). These municipal and sheriff's departments ranged from 21 to 586 sworn, patrolling jurisdictions that averaged 100,000 population.


In all, these agencies recorded 1,085 street incidents during last year in which suspects ended up restrained in a prone position, representing less than 0.8% of total arrests. Following a data-collection template, a designated supervisor at each agency transferred relevant information from officers' incident reports, addressing some 40 different variables. Ross then analyzed and interpreted this raw data.


WHO GETS PRONED. The vast majority of proned subjects (88%) were male and most (87%) were suspected by arresting officers of being drunk, drugged, and/or mentally ill. Their average age was 37.


In about 30% of cases, Ross says, "the subjects showed five or more characteristics indicative of excited delirium syndrome": non-responsiveness to verbal commands, extreme strength and violence, tireless and constant physical agitation, high pain tolerance, partial or no clothing, rapid breathing, profuse sweating, and generally "bizarre behaviors."


Most often, officers encountered them on vehicle stops, mental health calls, disturbances, assault/battery complaints, domestics, warrant service, and suspicious person/welfare checks.


Their resistance ranged from defensive moves (pulling or twisting away) to violent, aggressive attacks, including gun grabs and choking. Most (81%) used only feet, hands, or head as weapons, while about 1 in 5 grabbed "objects of opportunity" at the scene. Only 4% used an edged weapon, 2% a gun, and 10% a vehicle.


OFFICER RESPONSE. "Nearly all officers made some attempt to control the situation with verbal commands," Ross says. But typically some force escalation, usually involving a combination of tactics, became necessary. Control holds (73%), a CEW (19%), a hobble (19%), stuns/strikes (18%), and/or OC (14%) were most commonly applied. "As these figures show, officers are not Tasering everyone, as civilians often seem to believe," Ross notes.


Where CEWs were deployed, they were normally "directed to preferred areas," Ross says--to the back side of the resister's torso, shoulders, or legs. 77% of the time they were in probe mode and 85% of the time they were in drive-stun mode. In 85% of cases, no more than two trigger pulls were made.


Weight was applied to the back of proned subjects to aid in restraining them in nearly 7 out of 10 cases, Ross found, and 65% were kept prone while under weight for 30 seconds to 4 minutes.


RESULTS. Despite officer actions that critics have alleged carry dire risks, "80% of proned subjects suffered no injury whatsoever," Ross says. Mild damage "indicative of continued resistance" (bruises, cuts, scrapes) was experienced by 16%, while only 4% sustained "more significant injuries," such as "fractures, severe strains, or severe lacerations." These also were "likely due to the subject's own resistance," the study found.


"It is important to note," Ross says, "that even when subjects were Tasered, even when weight was applied to them while they were down, and even when their legs were hobbled, there were no deaths and extremely few significant injuries."


In his ILEETA presentation, he emphasized: "No reliable, scientific human study has found evidence that prone positioning causes death, just as no reliable, scientific human study has found evidence that CEW application causes death. Other studies strongly suggest that in-custody deaths are more validly associated with such factors as toxic drug use, exhaustive mania, pre-existing cardiovascular conditions, internal organ abnormalities, diseases, and protracted physical struggling, unrelated to prone positioning."


As a control measure, Ross asserts, "prone positioning is preferred for the safety of officers and subjects alike." He recommends organized team tactics for getting combative subjects "to the ground, controlled, and restrained as quickly as possible." He explains that this "shortens the confrontation time span and allows the subject to promptly receive medical attention."


With a handcuffed subject turned on his side when it is safe to do so, "an officer can then be assigned to monitor the subject's face for any signs of distress," Ross recommends. He stresses the importance of getting EMS en route as soon as possible when dealing with a resistant subject and of communicating frequent radio updates--"creating a 'Motorola memory' "--on what's occurring throughout the contact.


In his presentation, Ross cited an earlier field study on prone positioning conducted in Canada that reached findings similar to his. This investigation was led by Force Science faculty member Dr. Christine Hall and was reported by Force Science News on 1/30/12 in transmission #196. Click here to read it or visit:


Publication of Dr. Ross's new study in a professional journal is pending. He is at work on a book about sudden in-custody death investigations. He can be contacted at:



III. New findings on obese subjects & prone positioning


Shortly before Dr. Darrell Ross's ILEETA report, results of another new study on prone positioning were released by a research team from the Department of Emergency Medicine at the University of California's San Diego Medical Center.


In light of allegations by some critics that obese subjects are especially susceptible to adverse outcomes when proned out after struggles with law enforcement, this group tested various physiological effects of prone positioning on 10 significantly overweight volunteers after periods of intense exercise.


These subjects were monitored for heart rate, blood pressure, carbon dioxide levels, and breathing efficiency in three positions: seated with their hands strapped behind their back, prone with their arms to their sides, and hog-tied while prone.


Finding: There were no clinically significant detrimental effects detected among the three positions.


A free abstract of this study, "Evaluation of the ventilatory effects of the prone maximum restraint position on obese human subjects," can be accessed by clicking here. A full report of the research is available there as well for a fee.


Our thanks to two sources who brought this case to our attention: Dr. Mark Kroll, adjunct professor of biomedical engineering at the University of Minnesota and California's Cal Poly University, and Michael Brave, ILEETA instructor and manager/member of LAAW International, LLC.


IV. Latest news on OIS that occurred inside an accelerating van


A federal civil rights case we've followed in previous transmissions, involving an Anaheim (CA) officer who fatally shot a driver who had trapped him inside a speeding van, may be headed to the U.S. Supreme Court.


A majority ruling by the full 9th Circuit Court of Appeals sitting in San Francisco recently overturned a lower court decision that had granted summary judgment favoring the officer, who is accused by survivors of the suspect of using excessive force in his desperate effort to get the vehicle stopped.


The appellate majority held that a verdict supporting the officer's use of deadly force was not the only conclusion a reasonable jury could reach, in light of inconsistencies in testimony as to whether the vehicle was accelerating fast enough to pose an immediate threat to the officer's safety. Thus, the court declared, the case should go back to the district level for trial.


An especially strongly worded dissent by Chief Judge Alex Kozinski and three other justices asserted that "the only thing this will accomplish is to give plaintiffs a bludgeon with which to extort a hefty settlement. The Supreme Court should foil the plan with a swift summary reversal."


Anaheim Asst. City Atty. Moses Johnson, who has led the defense in the case, has 90 days to appeal. "If the city decides to proceed," he told Force Science News, "I hope the Supreme Court will actually accept the case for hearing."


Meanwhile, a trial date in district court is pending and probably lies a year or so down the road, Johnson estimates.


To read the recent appellate decision in full, click here


For our earlier coverage, see FSN #250 (2/26/14) and #251 (3/11/14) which can be found in the Force Science News Archives under "newsletter" at:



V. FS faculty member trains feds to interview "Persons of Concern"


Under the auspices of the U.S. State Dept., a faculty member for the Force Science Certification Course is training federal agents in techniques for interviewing and evaluating potentially dangerous individuals.


The instruction is being conducted by Dr. Edward Geiselman, a UCLA psychology professor and independent law enforcement trainer, for personnel assigned to the department's Diplomatic Security Service and Protective Intelligence Investigations Division and to the Joint Terrorism Task Force.


Among other duties, these agents are responsible for monitoring so-called "Persons of Concern" (POCs), individuals who have drawn attention through their behavior or written or oral statements as possible threats to governmental dignitaries.


"Assessing Persons of Concern can be very difficult," Geiselman explains. "They often are mentally challenged and most have not yet broken any laws, so they have to be evaluated through consensual conversations."


Geiselman, co-developer of the Cognitive Interviewing technique for peace officers, is briefing the agents on how to apply principles of that protocol to their work, as well as outlining methods for developing rapport to elicit cooperation and for detecting deception and assessing truthfulness.

© 2017 Force Science Institute Ltd.