Louis Theroux returns this Sunday (BBC2, 9pm) for a new series exploring Los Angeles, beginning with a look at those whose lives revolve around the city's huge canine population.
In this clip released by the BBC, the documentary maker visits a training school in Compton that caters to people concerned about crime and looking to weaponise their dogs. The result is a close encounter with a Dutch shepherd by the name of Prowler that left Theroux shaken:
"I felt total fear," he tells Radio Times. "Those dogs are trained to maim anyone that wishes to do their owner harm - my heart was beating so fast I thought it was going to burst out of my chest. I'd like to think I was quite brave to do it. Usually, we'd have a recce beforehand, but this was a spur of the moment decision. I just thought, 'Well, this is the moment I have to experience the terror of being mauled by a dog that's been trained to be weaponised.'"
But there was also the worry that he wouldn't be left with his dignity intact: "My other concern was that my trousers were going to fall down. I was wearing those fashionable jeans that are tight around the leg but baggy at the top, so I have one padded arm being bitten by Prowler and the other trying to keep my trousers up. I was panicking that BBC2 viewers were going to end up seeing my underwear."
You can read the full interview with Louis Theroux in this week's Radio Times and watch the scene itself below: