Although many Americans were confused and some were angered by the jury's inability to agree on Nichols' sentence, legal analysts say the justice system worked in both trials.
"There was a ton of evidence linking McVeigh to the crime," said Denver attorney Andrew Cohen, a legal analyst on both bombing trials. "You had far less evidence against Nichols than you had against McVeigh and I think that's the ultimate truth about this Nichols trial.
"I think that justice was served in the first trial and, I think, that the result of this Nichols trial, when the judge sentences Nichols, will be about as close to justice as I can imagine."
Christopher Mueller, a University of Colorado law professor, noted that Nichols wasn't in Oklahoma City when the bomb was detonated, and the defense skillfully raised doubts about whether Nichols helped McVeigh build the bomb.
"A verdict of death for Timothy McVeigh and a verdict of a long prison term for Terry Nichols is a just outcome," he said.
Prosecutors have said McVeigh and Nichols, who became friends in the Army, plotted the April 19, 1995, bombing of the Alfred P. Murrah Federal Building to avenge the deaths of 81 people in a federal raid on the Branch Davidian compound near Waco, Texas, two years earlier.
Seven months before the blast, prosecutors say, the two began acquiring the key ingredients for the bomb -- 4,000 pounds of fertilizer, racing fuel and explosives.
The government alleged they met at a fishing park near Junction City, Kan., to pack the bomb inside a Ryder rental truck on April 18, 1995. When McVeigh detonated the bomb the next day, Nichols was at home with his family in Herington, Kan. The blast killed 168 people in the worst act of terrorism on U.S. soil.
During McVeigh's trial, prosecutors played on their strengths, such as McVeigh's hatred of the government and his letters threatening federal agents.
They skirted the questionable parts, such as the lack of a single eyewitness who could place McVeigh in Oklahoma City.
McVeigh's 3 1/2-day defense raised questions about the FBI's investigation and key prosecution witness Michael Fortier, an admitted habitual drug user.
In the jurors' minds, McVeigh grew guiltier with each passing day. "There is no justification for that kind of action," juror Tony Stedman said shortly after the death-sentence verdict.
During Nichols' trial, prosecutors wove McVeigh's involvement through the weaker, more obscure evidence against Nichols, but their presentation wasn't as compelling and defense attorneys proved more adept at poking holes.
Prosecutors called two witnesses who placed a Ryder rental truck at the Kansas park; defense attorneys called several more who saw Ryder trucks at the same lake as much as a week before.
The government lacked any witnesses who could identify Nichols as the man who bought fertilizer, stole explosives or robbed a gun collector to get money for bombing operations.
The defense called witness after witness who testified about seeing McVeigh in the critical days before the bombing with men other than Nichols, raising the possibility of other co-conspirators.
And, the defense challenged the FBI investigation by pointing out a 9 1/2-hour interview with Nichols wasn't tape-recorded and drill bits allegedly connecting him to the quarry break-in had rusted in an FBI lab flood.
The jury convicted Nichols of conspiracy and involuntary manslaughter, but couldn't agree on the extent of his involvement or on a sentence. U.S. District Judge Richard Matsch will sentence Nichols, but no date has been set.
The verdict was sharply criticized by bombing victims' relatives and survivors and others in Oklahoma, where there are plans to try both men on 160 state murder charges.
"This was the most monstrous act of terrorism ever in the history of the United States. The people who did this deserve the death sentence and certainly life in prison -- and that hasn't happened here yet," said Oklahoma Gov. Frank Keating.
Vera Chubb, who served on McVeigh's jury, said she believed Nichols was deeply involved with McVeigh.
"They had two years to plan this. If I knew of a friend or anyone that I thought was going to do this horrendous crime, I would have said something," she said. "I was completely dismayed by this jury."
Cohen believes there was enough evidence to convict Nichols on all counts, but said it was so ambiguous that "it was entirely reasonable for 12 people also to find there wasn't enough."
"I think another 12 people might likely have seen the case a different way and there might have been convictions on all counts and a death sentence," he said. "From these jurors, you get the sense every time they had to give the benefit of the doubt to someone, they gave it to Nichols and whether we believe that's right or not, that's the law."