Tim Larkin is not a man who minces words. "The human body is very susceptible to trauma," he explains. "Disengaging the brain from the body is what we're trying to do – you have to stop the brain's ability to control the body."
As a former military intelligence instructor who helped America's elite Navy Seals develop their hand-to-hand combat techniques, the San Diego-born 45-year-old has spent two decades learning about violence.
In that time he has come to a controversial conclusion: that the only way to really defeat an attacker is to take the fight to them and injure them to a level where they can no longer continue. And later this month Mr Larkin shall impart such knowledge to 90 ordinary citizens who have agreed to pay him £200 for a two-day seminar in Slough.
"Probably the most controversial thing that we advocate is to focus on stopping someone via causing an injury, rather than trying to block an attack," he says, in a soft southern drawl surprising from a man built like an all-American wrestler and who boasts he can teach people how to kill "in four moves".
"The person who survives a violent attack usually does so by fighting back and injuring the other person rather than protecting themselves," he adds. "When you look at the videos of real violence, real fights, it is the people who try to block or protect themselves that end up getting stabbed, kicked or punched to death."
It is a lesson far removed from the more traditional martial arts which tend to emphasise the purely competitive and defensive nature of their sports and shy away from advertising their techniques as a means to stop an attacker dead – even if many devotees sign up for just that reason.
The lesson is one that members of the public are increasingly eager to buy into, especially young male and female clients who want to learn defensive fighting techniques applicable to everyday scenarios such as knife crimes.
Newer schools of fighting styles such as Krav Maga, a form of unarmed combat pioneered by the Israeli Defence Force and adopted by security professionals worldwide, have reported a large increase in citizen advocates in the past few years. There are now three Krav Maga facilities operating in London alone, and membership has increased by 800 percent in the past four years.
Which is why Mr Larkin believes now is a good time to bring his unorthodox defensive techniques, known as Target Focus Training, to the UK. He has been teaching corporate clients, military and law enforcement agencies for two decades. But more civilians want in, so he spends half his time teaching them, and makes two trips a year to the UK.
"When I first came to Britain I mainly trained corporate employees who were working in relatively dangerous Third World countries or wild west environments," he explains. "In the last 10 years I've started having everybody from London cabbies to housewives. About 70 per cent of people come to me when an act of violence has happened to either them or someone they know. And they are concerned because they don't know how to respond."
One Slough councillor has highlighted the risks that people could misuse such techniques. Mr Larkin answers that ordinary, law-abiding citizens should have the right to learn how to defend themselves. He won't teach any males under the age of 18, because, he says, "young men tend to glorify violence and like to experiment too much". Otherwise, he believes anyone should be welcome to attend.
"If you choose to ignore the tool of violence, then it is only going to be available to the predators," he says.
So what does he actually teach? In the middle of Hyde Park, surrounded by office workers taking a jog or snacking on their lunches, Mr Larkin gives me a demonstration on how to fight back at someone who is holding a knife to your throat.
"A lot of the martial arts schools will teach you clever-looking techniques that look great but don't actually work in the real world," he says. "But what you've got to do is inflict enough pain for your opponent to literally seize up."
Rather than concentrate on the knife itself, he advocates going for one of a number of soft spots on the body that will inflict enough pain for your opponent to entirely stop what they are doing – namely holding you at knifepoint.
In order not to give readers ideas without full instruction, I won't go into the details. But suffice to say, if performed correctly, the move he taught me would leave an opponent on the ground with a burst eardrum, swollen testicles and a broken ankle in a matter of seconds.
Most of what he teaches comes from his military background. The father-of-one joined the US Navy in his teens and missed out on graduating as a Seal following a diving accident which lacerated both his ear drums. Instead he joined military intelligence, and began working with the Seals on developing their fighting techniques.
While his techniques might be useful to elite soldiers or undercover drug enforcement officers, must civilians really be armed with such knowledge? After all, everyday citizens have a right to defend themselves, but only if it that response is proportionate.
Mr Larkin's response is typically uncompromising: "Here's the issue with 'proportionate response': it is a great theory, but the only ones who are actually concerned by it are law-abiding citizens. Most of the time you're facing someone who is going to use a disproportionate level of violence, and most likely you'll be facing multiple attackers."
The key, he insists, is knowing and teaching people when to respond to violence with violence. "It's a matter of choice," he explains. "Generally if there's choice in the matter, most likely it's the wrong time to respond."
He teaches his clients to categorise violence in two ways: antisocial and asocial violence.
"In antisocial behaviour we may goad each other, we may push each other, but we're still communicating," he says. "Asocial behaviour is where the head drops, the knives come out, nobody talks, and you're just trying to end another human being. Those are the events that I am talking about, those are the events that people come to me for."
It is the ordinary citizen's unwillingness to resort to violence when the chips are truly down that leave us vulnerable. To illustrate this he leans on the somewhat extreme example of the Virginia Tech shootings, when 32 people at the American university were shot dead by fellow student Seung-Hui Cho. But he insists the same is true of violent muggings.
"Many people literally watched him [Seung-Hui] reload his weapon multiple times and he was a small man," he says. "Right after that a bunch of my Israeli friends called me and they said, 'Why didn't they swarm him?' When a population lives with the threat of violence, they know how to use it against perpetrators when necessary. Here in the West we're not willing to do that, and it leaves us frighteningly vulnerable."
Big hits: The new martial arts
Invented by a Hungarian Jew in the 1930s. Tired of increasing anti-Semitic attacks in the run-up to the Second World War, Imi Lichtenfeld used his wrestling and boxing skills to develop an easy-to-learn technique. The Israeli Defence Force later adopted it and refined Lichtenfeld's inventions into an unarmed combat technique used by special services and bodyguards around the world.
*Mixed Martial Arts
An amalgamation of virtually every martial art that has developed into a popular sport under the Ultimate Fighting Championship banner. A number of British fighters now compete at the highest levels. Particularly popular in the North.