Shoot to stun
British low key policing has been admired for decades, with the UK
Government committed to finding alternatives to firearms.
NATO calls these substitutes, such as baton rounds, water cannon and
CS gas, ‘non-lethal weapons’. Others prefer the label ‘less
lethal weapons’.
The increasing variety of such weapons has been investigated by an
independent commission and working group on the future of policing in
Northern Ireland, involving the Northern Ireland Office (NIO), various
government offices and the Association of Chief Police Officers (ACPO).
It has led to a short list of preferred less lethal weapons, but these
require independent investigation into their medical effects –
which is where the renowned trauma and vulnerability experts at Dstl
Porton Down come in.
They have been asked to concentrate on four less lethal weapons options
identified by the Patten Report and ACPO:
Kinetic energy rounds
These range from large ‘plastic bullets’ and beanbag rounds
to sock rounds and even tennis balls.
The major concerns with this type of weapon are accuracy, effective
range, and possible impact to the high-risk areas – the head or
chest.
Nearly all deaths from baton rounds in the UK have been from strikes
to the head - the last in 1989. Recent systems and guidelines have significantly
improved safety, principally by improving accuracy and reducing dispersion
of the projectiles.
Electrical incapacitators or ‘tasers’
The electrical incapacitator is arguably the most controversial and
least understood less lethal weapon currently available.
Some are of the stun gun variety, which are held against the offender,
but the longer range ‘taser’ is being considered for police
use in the UK - ‘taser’ is an acronym for ‘Thomas
A Swift’s Electrical Rifle’, after the Tom Swift science
fiction fantasies written from 1910 to 1941.
The pistol or torch-shaped taser shoots two wire-trailing darts designed
to attach to the offender’s body or clothing – the darts
themselves raise a risk of injury, particularly to the eye. After contact
the user triggers an electric current to immobilise the target.
Tasers have been used in the USA for 20 years but never in the UK,
where they are currently classed as a firearm. They are now being re-evaluated
as an alternative to firearms.
At least 16 deaths have been associated with their use in North America,
albeit nearly all in connection with people using drugs, so Dstl not
only has to check their general effect on people but also whether drugs
such as cocaine make the heart more vulnerable to the pulses. So far
there has been no evidence that a taser in isolation has directly killed
an individual.
Water cannon
Water cannon vehicles borrowed from Belgium have been used in Northern
Ireland for the last couple of years, but medical evaluation of possible
harm from the cannon’s jet is difficult.
Though there is an obvious risk of eye damage or injury from being
knocked down by the water jet, Dstl is developing a system to measure
forces applied by the jet on various parts of the body.
Irritants
Dstl Porton Down has conducted much research on irritants such as CS
because they are already available to British police and the Army.
Their drawback is dispersion - tackling a few troublemakers may also
affect innocent bystanders. The focus now is on the delivery of the
irritant to selected individuals, using projectiles, but this raises
the possibility of injury from the projectile.
Reducing serious injuries
Porton Down has an enviable reputation for investigating the effects
of trauma and injury and developing new and existing measurement techniques.
The Dstl technical leader behind the Biomedical Department team, says:
“Dstl has great experience in this field. We know how vulnerable
human beings are to injury and have developed ways to assess the risk
and severity of injury.
“Our expertise differs from similar capabilities in the automotive
safety field. Car crashes are still traumatic, but the rate of energy
transfer is relatively low compared with the localised forces and high
rates of energy transfer from the weapon types we are looking at.”
Dstl’s work requires liaison with organisations and manufacturers
in the USA, where many less lethal weapons can be bought ‘off
the shelf’. Although UK police and armed forces have long experience
of using baton rounds in Northern Ireland, US police have used less-lethal
options extensively.
Nevertheless, there is still a scarcity of research into the medical
effects of less lethal weapons and Dstl has had to customise or design
a range of new tests and computer and physical models, specifically
to determine:
• The accuracy or discrimination of the weapons and their risk
of affecting the two most vulnerable parts of the body, the skull and
the chest – and especially the brain and heart.
• The direct interactions of energy – kinetic, electrical
and chemical – on these two vulnerable areas and other parts of
the body.
In the case of tasers it was clear that, despite many years’
use in the USA, their effects were not really understood.
The team’s response has been to enhance its unique in-house computer
modelling system, developed to address concern about the effects of
pulsed mobile phones and military communications on tissue such as the
brain. This will determine where Taser pulses would flow - a particular
area of concern is the heart.
At the other extreme from this sophisticated computer modelling is a
comparatively crude, yet no less effective, rig used to model the effect
of a kinetic energy projectile such as a baton round hitting the skull.
The Dstl technical leader explains: “We use a cow’s scapula
to model human skull fracture. It is a simple, cheap, but validated
way to predict this life-threatening injury.”
But most Dstl research on predicting impact effects draws on new world-leading
techniques such as the organisation’s Behind Armour Blunt Trauma
(BABT) rig.
While Hollywood suggests that troops or police wearing body armour
can walk away unscathed after stopping a bullet, the effect of the armour
dispersing the bullet’s energy over a wider area can still be
traumatic.
This led Dstl to develop the BABT rig – a rubber body wall simulating
the dynamic properties of a real chest wall. When the ‘body’
is struck, laser-sensing elements measure how much it is displaced,
and over what time interval. Chest injuries can be predicted from these
outputs.
Top
|
