A man who murdered his boss and tried to kill three other people "in acts of callous wickedness, cruelty and inhumanity" was sentenced to life in prison today.
Russell Carter, 53, was found guilty of killing Kingsley Monk and three counts of attempted murder after a three-week trial last month.
He was told today he would serve 30 years in prison before he is eligible to apply for release.
Mr Monk, 45, was strangled, probably with his own tie, at Driverline 247 in New Inn, Pontypool, south Wales, last October, Newport Crown Court heard.
He was bound and gagged by Carter, who repeatedly kicked him and beat him with a piece of pipe.
Three other men, Gethin Heal, Nathan Taylor and Robert Lewis, were also tied up and doused with fuel as they arrived for work.
Carter, of Rumney, Cardiff, launched the lethal attack at the office, brandishing what he was later to claim was a toy gun and claiming he was owed £3,000.
He fled the office after setting it on fire with the intention of killing the three witnesses still inside.
Sentencing, Recorder of Cardiff Judge Nicholas Cooke QC told Carter: "These crimes were acts of callous wickedness, cruelty and inhumanity which beggar belief.
"The murder was frenzied and horrific. You terrorised Mr Monk before killing him. Your intention was to kill and you killed."
Addressing the attempted murders of the other men, the judge said: "Here your intention was evil. The fate you meant for these three men was horrific.
"It showed your unfeeling cruelty. You wanted them to die, either by being burnt alive or by asphyxiation as they lay bound and helpless.
"Whatever your grievance with Mr Monk, these men had done you no conceivable harm. That you intended so terrible an end to those who had done you no harm identifies you as both extremely dangerous and thoroughly bad."
After returning its verdicts, the jury - nine of whom were in court to hear the sentencing - was told that Carter committed a violent armed bank robbery in the US years before he returned to Britain and killed his boss.
But because no formal agreement exists to alert the UK of his criminal past, the authorities here did not know until the Newport trial was already under way.
It meant Carter was able to work as a lorry driver while in breach of parole in the US after serving part of a 20-year jail term there.
The defendant, who delayed proceedings for an hour because he said he could not summon the dignity required, remained impassive throughout as the judge sentenced him to 25 years for the attempted murders and 10 years for false imprisonment, to run concurrent with his sentence for the murder.
The judge acknowledged he would probably die in prison.