In Britain, Katherine's murder has sparked fears about the safety of backpackers. Any parent with an adventurous child must have wondered what they would have done in a similar situation as they listened to the words of Ian Horton.
He was nervous about his 21-year-old daughter travelling to another continent. But she had tried to reassure him that she could just as easily be knocked down by a bus at home.
"She was full of confidence," he said. "She felt immune to the dangers of the world, as we have all felt when we were young adults. She came to Thailand to dance on a beach, to ride an elephant. Tragically her faith in her fellow man let her down."
In Koh Samui, Thailand's fastest growing tourist destination, emotion still rides high.
"I am very angry about what happened," said businessman Piya Chanthong, the owner of a complex of beachside apartments near where Katherine had been staying. He is campaigning for more control over development and extra police officers for the area. "The people who did this have nothing in their heads," he said. "They just drink and watch porn and decide they have to find a lady to rape. In Samui foreign girls have been raped before, but not killed. To rape and kill is very unusual here. That is why everyone is so angry. They are afraid that it is going to make people hate Thailand."
Fifteen years ago, Koh Samui was a backpacker's secret -- a sleepy and unspoilt coconut and fishing island. Then came the dream of The Beach -- the film based on Alex Garland's novel starring Leonardo DiCaprio. The island from which tourists visit the film's location was, before the tsunami hit it, so overbuilt that the water supply had been irretrievably poisoned by tourists' waste. These days Koh Samui now rivals Phuket as one of the country's most popular destinations. It has recently experienced a triple boom, benefiting from a financial crisis which suddenly made Thailand very cheap for visitors, the 2002 Bali bombing which discouraged people from going to the Indonesian island, and the 2004 tsunami which devastated the west coast of Thailand but left Koh Samui unscathed.
Last year, during high season, it was so busy that some tourists were found sleeping in temples. For some it is all good news -- property developers, the sex trade, wealthy expats and ex-cons are reaping the benefits. Others -- mainly backpackers, poor uneducated Thai people and the environment -- are paying a heavy price. Although still unarguably beautiful in parts, many of Thailand's main beaches and towns have been ruined by the trappings of Western tourism.
Lamai has been spoken about as the new Ibiza or Faliraki. Premiership football matches are shown in many bars, British newspapers are widely available. In addition to such influences, Lamai has also emerged as one of the largest and least regulated red-light areas in the country. It is not easy to find a bar there which is not a front for prostitution and many Thais say the scene is now far worse than the once notorious Patpong district of Bangkok.
There are around 10,000 prostitutes in Samui alone. Thai officials have an uncomfortable relationship with this side of their country. At least 10 per cent of the total tourist spending is on the sex trade which, although illegal, is tacitly tolerated by the government because of the enormous sums earned from it.