New Study: “No Fatal Risk” In Proning Out Violent Resisters

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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.


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.


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.


“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.


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. Click here to read it or visit: https://www.forcescience.org/2012/01/is-prone-positioning-really-riskier-for-suspects/

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: dross@valdosta.edu

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