A security guard was today found guilty of murdering a delegate at an HIV conference at the SECC in Glasgow by battering her with a fire extinguisher.

Clive Carter, 35, from Motherwell, smashed 42-year-old Khanokporn Satjawat repeatedly over the head and face with a fire extinguisher in a rage because she complained about him checking her security pass.

Every bone on the left side of her face and neck were broken and her skull was shattered into pieces. She died from blunt force trauma.

Ms Satjawat also had defensive injuries to her left hand caused by 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 snapped after Ms Satjawat became annoyed when he demanded to see her ID, and claimed she was abusive to him.

The defenceless delegate was killed by the man prosecutor John Scullion described as "being paid to ensure she was safe."

Carter, who worked for G4S, admitted killing Ms Satjawat, but denied murder, claiming he had no memory of the incident. He said his next memory 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.

But jurors at the High Court in Glasgow rejected his excuses and yesterday 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 a mystery Asian man carrying an extinguished in the aftermath of the killing.

He was also convicted of committing a breach of the peace at the Holiday Inn Express, Stockwell Street, Glasgow, on November 4, 2012, by knocking on the door of a room while carrying a fire extinguisher and claiming there had been a report of a fire.

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 the counsellor annoyed him.

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 dead of 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."

Before sentencing Carter, Lord Matthews went off the bench to consider victim impact statements from Ms Satjawat's sister and the woman he terrified in a hotel room eight days before the murder.

Detective Superintendent John McDonald 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."