Peter Clarke took an axe, a knife, a bullwhip and a set of brass knuckles to work at Dualways Bus Company on May 7, 2006.
When he got there, he commandeered a 53-seat single decker coach and drove it out of the yard.
Mr Clarke spent the next few hours cruising around Dublin until his boss spotted him outside Heuston Station and approached him to find out what was going on. He was supposed to ferry passengers in a shuttle bus from a Fine Gael Ardfheis at Citywest to the train station. He was in the wrong bus.
David McConn noticed, as he stood in front of the coach, that Mr Clarke was smirking below his sunglasses. He thought this unusual for his usually quiet, withdrawn employee, who had asked for a day off the previous week to go to a priesthood interview.
After a five-second stand-off, he heard the driver rev the bus's engine and suddenly charge towards him. He jumped out of the way and saw the smirking Peter Clarke break red traffic lights and speed off toward the Naas Road on a rampage that left people injured, vehicles wrecked and one 62-year-old mother dead.
Pauline Walley, prosecuting, described the episode as an "Odyssey of destruction" on Day 1 of Mr Clarke's trial at Dublin Circuit Criminal Court last week.
The accused sat sedate behind the witness box in the airy courtroom, his great jowly head drooping over his slumped bulk. His face hung still, gazing vacantly at a nearby floor spot; no signs of the manic, snarling coach driver many garda witnesses saw laugh and grind his teeth as he charged at them and rammed their vehicles during the Sunday afternoon rampage.
Angela Buckley's clear young voice faltered slightly in the witness box when she spoke of her dead mother. Tears threatened to break her composure as she recalled seeing her mum lying still on the road in the destruction trail of the rampaging bus.
In the moments before she was swept away, Ms Buckley pressed her hand against her daughter to push her free of their car. She couldn't get out her door properly because of its proximity to the Bluebell Luas stop railings and the bus, with an unmarked garda car attached to its grill like a snow-plough, bore down on her. One witness said in a statement read out in court, that she saw the lady fall under the bus and roll along with it until it dumped her on the road. She died instantly.
The young Ms Buckley didn't have to give evidence under the courtroom glare. It was her choice.
Doctor Henry Kennedy, Clinical Director at the Central Mental Hospital, said Mr Clarke suffers from paranoid schizophrenia with a history of psychotic episodes in Ireland and the US.
The day of his rampage, he was convinced that gardai, in league with British forces, were trying to assassinate him because he refused to turn IRA informer.
Dr Kennedy said the former City of London Police constable understood basically what he was doing when he pummelled his way with the bus through oncoming traffic at the Naas Road Bluebell junction. The doctor said he was vaguely aware he rammed garda cars before he swerved across the junction, scooping up a blue unmarked Ford Mondeo on the way towards the traffic. He said Mr Clarke knew he hit cars and, despite not understanding the consequences of his actions, understood what he did.
Dr Kennedy concluded that Mr Clarke was fit to plea in a criminal trial because of this understanding.
A psychiatrist witness for the defence, however, said Mr Clarke didn't understand his actions. Prof Patricia Casey said he told her he'd been very upset in the months leading up to his rampage. He said this upset started when an Irish Army sergeant encouraged him, on St Patrick's Day, to infiltrate the IRA. When he refused to turn informer, he was convinced he became a garda target for abuse.
The day before he took the bus, he said he went to Cathal Brugha Barracks and asked for a rifle. He didn't get it and woke up the next day after a good sleep feeling angry.
Prof Casey said Mr Clarke was "too agitated, too perplexed and too terror stricken to even consider right and wrong" when he went to work that morning with an arsenal of weapons.
He was diagnosed with paranoid schizophrenia in an American hospital after a mental breakdown in 1999. Before this he spent much of the Nineties living in England, convinced the IRA were hounding him for his firearms and MI5 harassing him for spy work. He brought the City of London Police Force to court in 1994 for racial discrimination and won £7,500.
Mr Clarke returned to Ireland in the late Nineties teeming with paranoia and received treatment in Tallaght hospital after a 1998 incident with a Dublin Bus coach in Rathmines where he alarmed the public about a Loyalist bomb threat.
He had varying success rates with anti-psychotic medication after his diagnosis but wasn't taking it in the months before the rampage.
A garda driver of the blue Ford Mondeo lodged briefly at the bus's grill and shunted sidelong through the line of civilian cars at Bluebell, recalled seeing Mr Clarke "snarl his teeth" before he rammed his car, a marked garda car and a civilian car.
Garda Peter Comerford said he thought the bus driver intended "to kill all the gardai in his path".
His unmarked car couldn't reverse fast enough and was snow-ploughed through traffic; the impact ripping chunks from it, forcing the three terrified gardai inside to crowd into the cabin centre.
He was amazed that he and his colleagues survived. Garda Comerford, who was trapped in his seat, gradually became aware of the lady lying on the road next to his car in the bus's wake.
The man who finally stopped Mr Clarke had been spending a quiet Sunday afternoon doing paperwork at Harcourt Square garda station.
Detective Sergeant Sean Hogan and his office colleagues dispatched in their vehicles to find the bus which was now speeding away from the Bluebell junction.
He caught up with the coach hurtling along the Naas Road in the direction of Rathcoole. He saw it defy attempts by gardai to shoot the tyres. He saw it charge at pedestrian gardai who threw a spike strip called a "stinger" device in its path. He saw it ram a garda patrol van on the Davitt Road, which ploughed into a van and trailer spilling debris over the carriageway.
By the time Mr Clarke burst through the wooden gates and sped into Dualways bus yard, there were up to 20 garda vehicles and the garda helicopter chasing his tail.
Det Sgt Hogan decided to act fast in the seconds it took Mr Clarke to turn his bus around for a swift exit back through the broken gates. Garda cars clogging up that narrow yard entrance had nowhere to go.
The detective got out and began waving his arms frantically at the bus.
Mr Clarke took the bait. He changed the bus's direction and came directly at the flapping garda. Det Sgt Hogan stalled as long as he could and at the last moment, he darted to his left and the bus with its driver took a nose dive into an embankment.
He found the colossal driver halfway down the bus corridor wielding his weapons when he smashed through a window seconds later.
Mr Clarke lashed out with his axe, striking the detective on the head. He swung at other garda members filing into the bus with his knife and continued to headbutt, kick and bite once they had him face down on the ground outside the bus.
Det Sgt Hogan, a big man himself, said he never restrained such a strong, violent assailant in all his years in An Garda Siochana.
Mr Clarke was steadfast that gardai were trying to kill him. He claimed they were discussing murdering him as they held him down and stole things from him, notably his Rolex watch. He also claimed he tried to dial "911" on his phone when gardai had him pinned down in the bus aisle.
All garda witnesses involved in that final showdown commented on Mr Clarke's "goliath" and "phenomenal" strength, describing how they had to prise his fingers individually from the long knife he clutched in his right hand.
Several hours later, a calmer Peter Clarke asked to see a doctor in custody and was given antibiotics washed down with a glass of milk.
Since events two years ago, Mr Clarke has expressed considerable remorse for "what happened to the lady", according to Drs Kennedy and Casey.
He told them: "It weighs heavily on me what happened to the lady. I didn't see it happen but I believe I knocked her down and killed her. It weighs heavily on my soul."
Mr Clarke prays for the mother who had been on her way with her daughter to a relative's First Holy Communion meal, the mother who thought of her girl's safety first.
Tomorrow, counsel will make their closing speeches and a jury of eight women and four men will begin deliberations on the charges facing Mr Clarke.