A top professor who beheaded his PhD student lover was overpowered when he grabbed a sword during a police crime scene reenactment aiming to kill himself.
Leading Russian military historian Oleg Sokolov, 63, has confessed to stabbing and dismembering 24-year-old Anastasia Yeschenko before disposing of her body parts in a river.
The Napoleon expert was taken from his custody cell to his luxury St Petersburg flat to show detectives how he committed the murder as part of the criminal investigation.
With his handcuffs off he tried to grab the Napoleonic sword but was stopped by officers, say law enforcement sources.
His lawyer Alexander Pochuev said: 'The defence can only confirm that he tried to commit suicide.
'He was stopped by policemen. There was no threat to third parties, the act was aimed only at himself.'
He had been taken to the reenactment wearing a police helmet and bullet proof vest for his own protection.
The sword had been lying on a table.
During the reenactment he demonstrated on a mannequin how he killed the PhD student and cut up her body using a saw.
The victim's grieving mother today claimed Anastasia had told Sokolov she was leaving him - and she believes this triggered his violent attack.
Galina Yeschenko, a 49-year-old police Lt-Colonel, said: 'She just got fed up with total control by Sokolov, and she told him that she was leaving.'
The mother told Moskovsky Komsomolets newspaper she had earlier urged her daughter to leave a man old enough to be her grandfather.
Pochuev said Sokolov was 'tormented' after shooting his lover four times and dismembering her body.
'He repents,' he said. 'He wants to apologise to the family, to the extent this is possible and wishes to correct the situation.'
The lawyer claimed the killing may have happened because of a full moon.
'It is a known medical fact that many schizophrenic debuts… happen this time,' he said.
Sokolov is in custody pending the murder investigation.
He faces up to 15 years in jail if convicted.