Until this last hurdle, however, the wheels of justice in the United States seemed for once to run relatively smoothly.
It took the US authorities just two days to hunt down McVeigh, two years to build the case against him, but just two mercifully short months to try and convict him.
From the first Judge Richard Matsch, a Colorado rancher when not in robes, was determined to avoid another media circus. He banned television cameras and gagged lawyers. He barred the defence from pointing the finger at international terrorists, or exploring loose connections between the bombing and notorious figures on the American far right. Like the case against OJ Simpson, however, McVeigh's prosecution was based on circumstantial evidence.
The government had evidence of motive and intent, but produced no eyewitnesses who put him at the crime scene, nor a confession. It left missing links for the defence to exploit.
Prosecutors used the survivors of the bombing like a Greek chorus. Under the excuse of proving, as required, that the bomb caused death, one building worker after another described making coffee and gossiping on the fatal morning with scores of people they never saw again. Prosecutor Joseph Hartzler told jurors that the bombing was a premeditated act, planned up to nine months before.
McVeigh's anger against the government dated back to his army days; it sharpened during the siege of the cult compound at Waco, Texas, where he believed David Koresh and his followers were intentionally murdered by Federal agents.
In the late summer of 1994, he was ready for action. McVeigh and Terry Nichols, a former soldier and farm hand who also faces the death penalty and will be tried separately, bought nitro-methane fuel at a race track, two tons of ammonium nitrate fertiliser at a farm store, and stole five blast caps from a quarry, it was alleged.
McVeigh rented the truck under a false name, and two days later parked the bomb in front of the Alfred Murrah building. Prosecutors produced a receipt for one ton of ammonium nitrate with McVeigh's fingerprint on it.
Their forensic evidence included traces of the same substance on a shard of the truck, and traces of explosives on McVeigh's ear plugs and the clothes he was wearing when arrested, allegedly from a blast cord.
McVeigh's beloved sister, Jennifer, reluctantly testified that he had warned her to lie low in late April and May. Lori Fortier, at whose wedding McVeigh was best man, testified that he showed with soup tins how he would place the 55 gallon drums of explosives in a triangle, to aim the blast at the building.
But it was her husband Michael, McVeigh's army buddy, who was the star witness, claiming that McVeigh planned the bombing to launch a war of revolt. "We both believed that the United Nations was actively trying to form a one-world government," including plans to "disarm the American public, take away our weapons," Fortier said.
Five months before the bombing, he said, McVeigh showed him the target in Oklahoma City, even the side street where he would park his getaway car.
In a skilful piece of timing, it was after Stephen Jones, McVeigh's attorney, had aggressively challenged Fortier that prosecutors produced a key, found in the street he had indicated, that matched the Ryder rental truck. While powerfully compelling, however, the case was not cut and dried.
McVeigh's anti-government rage was shared by thousands if not hundreds of thousands of Americans. The forensic evidence seemed thin, certainly compared to the victim's blood allegedly found in OJ Simpson's house, car, and on his socks.
A critical report on the FBI's laboratory, claiming technicians had based their findings on a list of ingredients from the investigation and not their results, had forced the prosecution to remove four scientists from its witness list.
The laboratory results "magically" fitted what the prosecution needed, the defence charged. Under cross- examination, office staff in Kansas, where the truck was rented, stuck by their original story: that they saw two men, one with the description that launched the celebrated manhunt for John Doe No 2.
From there, attorney Jones used the famous missing leg to suggest that there was a 169th victim in Oklahoma City - the true bomber. And others, he said, could be "still at large".
The defence charged that Fortier, who at first denied any knowledge of the plot, and declared McVeigh innocent, came under heavy pressure to deliver his friend's head on a plate.
Fortier faced a 23-year sentence after pleading guilty to conspiracy. His wife was threatened with the loss of her children, Mr Jones alleged, and both had a history of using alcohol and methamphetamine (speed). Both, too, were under the taint that they knew of the plot, and could have stopped the tragedy.
On the last day of the defence evidence, Mr Jones played FBI wiretaps from Fortier's phone, days after the bombing when he still denied any knowledge of it. "The less I say right now, the bigger the price later," Fortier is heard saying: "Talk about a career. I could spin a fable. I can talk all day."