Clive Carter has been found guilty of murdering SECC delegate A security guard has been found guilty of murdering an SECC delegate. Clive Carter was on trial accused of killing Thai pharmaceutical worker Khanokporn Satjawat at Glasgow's Clyde Auditorium in November 2012. The G4S worker had admitted bludgeoning the 42-year-old to death with a fire extinguisher, but denied murder. On Tuesday at the High Court in Glasgow, jurors returned a verdict of guilty after three hours and ten minutes of deliberation. Lord Matthews charged them to consider their verdict earlier in the day. The judge jailed him for life with a minimum of 20 years for the murder. Carter, of Motherwell, North Lanarkshire, killed Ms Satjawat while she attended a HIV drug treatment conference at the venue. Ms Satjawat died from blunt force trauma to her face and had defensive injuries to her left hand, sustained as she tried to fend off blows from Carter. Her watch was found beside her bloodied body. It was smashed and had stopped at a couple of minutes past 2pm. The murderer claimed he snapped after Ms Satjawat became annoyed when he demanded to see her ID pass on November 12 last year. Carter admitted killing Ms Satjawat, but denied murder, claiming he had no memory of the incident. He said his next memory following the confrontation with her was of eating sandwiches for his lunch. His lawyers, who urged the jury to find him guilty of culpable homicide, also claimed he had a personality disorder which diminished his ability to control his actions. Lord Matthews said Carter's personality disorder was of "little relevance" to the killing. Jurors at the High Court in Glasgow rejected his excuses and found him guilty of murder after three hours and ten minutes of deliberation. Carter was also found guilty of orchestrating a cover-up after the murder by washing blood off the fire extinguisher, hiding his bloodstained blazer and telling police he had seen an Asian man carrying an extinguisher in the aftermath of the killing. He was also convicted of committing a breach of the peace at the Holiday Inn Express in Glasgow's Stockwell Street on November 4, 2012, by knocking on the door of Stephanie O'Brien's room while carrying a fire extinguisher and claiming there had been a report of a fire. Khanokporn Satjawat: The Thai pharmaceutical worker was attending an SECC conference. The jury of eight men and seven women heard that Carter had major issues with anger management. His GP sent him to counselling, but he quit after two sessions because he said counsellor annoyed him. Jailing Carter, Lord Matthews ,said: "Khanokporn Satjawat was a hard-working , well-educated and dedicated lady who came to this country to participate in a conference whose purpose was the alleviation of suffering and the saving of lives. It is cruelly ironic that in the course of such an event of that the life of that fragile lady should be taken in such a brutal fashion with an instrument whose primary purpose is also the saving of life and the hands of a man to whom she should have been able to look for assistance. Lord Matthews told Carter: "You are plainly, on the evidence, a man who is disturbed. However, you are deeply disturbing as the evidence in this trial has amply demonstrated, including the evidence as to the events at the Holiday Inn Express. One is left to wonder what the outcome might have been had Stephanie O'Brien not had the presence of mind to extricate herself from the hotel room before the situation escalated.. However, your activities that night have understandably their left mark on her. You accepted responsibility for killing Khanokporn Satjawat. However, that accepting that you murdered her and it is plain that you took significant steps in the immediate aftermath of her death to cover your tracks. Lord Matthews told Carter it was up to the parole board to decide when, if ever he is released One of Carter's defence team, solicitor advocate John Paul Moberry, said: "Given the verdict of the jury there is very little I can say. Mr Carter approached this trial with the position that the death of this lady was caused at his hand. There has been evidence before the court of Mr Carter's medical state and there is nothing to add. Mr Carter has no relevant previous convictions and he has never been in prison before. The 35-year-old was described as violent and manipulative by his wife Paula in a police interview, jurors heard. Prosecuting, depute advocate John Scullion described Carter as "cold-blooded" and "devious." Detective Superintendent John McDonald of Police Scotland said: "We are satisfied that Clive Carter has been brought to justice for the murder of Khanokporn Satjawat. This was a particularly brutal and senseless attack which claimed the life of an innocent woman and caused fear and alarm to those who were attending the conference at the SECC last November. We would like to thank the management at the SECC and those who assisted in the inquiry who helped to bring this case to a satisfactory conclusion. We would also like to reassure the public that cases of this nature are extremely rare. We sincerely hope that this verdict will bring some comfort to the relatives of Ms Satjawat. A spokeswoman for the SECC added: "We are relieved that the court case has concluded so that the family and colleagues of Khanokporn Satjawat may now have some closure during what must have been a very distressing time."