However, a specialist at the Royal Thai Police's Scientific Crime Detection Division, speaking on condition of anonymity, affirmed that the components of a C4 bomb were found on the brassiere and Tshirt worn by Angkhana at the time of her death, which were not components of tear gas.
Angkhana, in her 20s, died while participating in the People's Alliance for Democracy (PAD) demonstration on October 7, 2008. Many investigators concluded that she died from the tear gas used by police during the crackdown on the protesters.
Central Institute of Forensic Science director Porntip yesterday said that a C4 bomb had components, including RDX. Thus when RDX itself was tested by any machine it would not yield a result as a C4 bomb, especially the Ionscan explosive detector that the institute had used in bomb attack investigations in the Southern violence for two years now, she said.
Porntip said tear gas could be divided into two groups: tear gas grenades that needed no explosive component, and the Chinesemade tear gas canisters and tear gas grenades used during the October 7 crackdown, which were found to have an explosive detonator that needed RDX as a component. She said this RDX - found Angkhana's clothes - was much likely to have come from tear gas not the C4 bomb. She said no lab device could detect a C4 bomb because they would only yield a result saying RDX was found while other substances mixing with RDX to make a C4 bomb were undetectable. She called for careful thinking before making public announcements, as some information should better be presented in a court or to the National AntiCorruption Commission.
Meanwhile, a specialist of the Royal Thai Police's Scientific Crime Detection Division, speaking on condition of anonymity, insisted the office could detected a C4 bomb using various protocols and tools together.
"The examination result of Angkhana's clothes, as previously announced, found four chemicals that comprised a C4 bomb. It is concluded certainly as a C4. This is not the first detection of C4, there have been detections before," said the specialist. As for the four types of tear gas used in the October 7 crackdown by police, he said there were no C4 components found, except for the Chinesemade tear gas that had the RDX substance.