From time to time, I've been asked to represent persons charged in federal court with capital crimes. The stakes in these cases cannot be higher. The litigation is both painstaking and intense. What is a federal capital trial like? Here are some details from a recent one.

The indictment in United States v. Williams, CR-11-298-F (W.D. Okla.) charged a murder at Fort Sill, Oklahoma. This historic Army post was founded in 1871 by President Ulysses Grant. Jurisdiction within the Fort's original boundaries is exclusively federal. The federal court for Oklahoma's Western District would hear the case.

A person charged with a federal capital crime is entitled to two court-appointed lawyers. The Williams court chose me as one of them. My colleague and co-counsel was Mark Henricksen, a talented and capable lawyer from Oklahoma City.

Capital murder trials have been quite rare in Oklahoma's Western District. The last one was held in 1926. Defending the District's first such trial in nearly a century was a sobering responsibility for both of us.

In 1789, the first Congress directed that federal capital trials be held in the county where the offense occurred. This law remains on the books today. It meant that the Williams case would not be tried in the Western District's busy federal court complex in Oklahoma City. Instead, the case would be heard in a small, seldom-used federal building in Lawton, Oklahoma. This vintage courthouse, opened in 1915, had not seen a federal criminal trial for many years. Some major modernizing was needed to get it ready for the Williams trial, which was expected to last at least a month.

In February of 2013, some 190 prospective jurors were summoned to Lawton from 12 counties scattered across western and southwestern Oklahoma. Due to the limited space in the federal courtroom, jurors initially convened in an old high school auditorium, now home to the Lawton City Council. There, jurors completed a 22-page questionnaire that would be used to guide later stages of the selection process.

During the next two weeks, prospective jurors were called back to Lawton and brought one at a time into the courtroom. Each was interviewed in depth by the judge and lawyers. The subject was the death penalty. For these jurors, capital punishment suddenly shifted from an abstract idea to something real and personal. What they had to say was fascinating.

Some jurors had never given much thought to the death penalty. Others told of deeply held beliefs, often closely tied to their faith and upbringing. And though the questions were gentle, a few jurors came to tears. Faced with the prospect of a life or death decision, individual emotions could run quite high.

When the juror interviews finally ended, we had a wealth of information about the people who would hear the case. Each side had 20 peremptory challenges, which could be used to remove any particular prospective juror. The two sides used their challenges to cull down the panel until only 15 persons remained. The first 12 would sit as jurors, and the remaining three would serve as alternates.

The jurors were sworn and opening statements delivered. Government witnesses were called and cross-examined. Soon it was Friday.

As we made ready to leave the courthouse on Friday afternoon, some stunning news arrived from Washington. Attorney General Eric Holder had authorized a plea agreement that would end the trial and spare our client from execution. But the agreement needed the trial judge's approval.

We immediately took our news to the judge. He had little to say, and gave us no sign that he would approve. A tense weekend followed, as we prepared for a third week of trial.

The winter weather turned icy over the weekend. Jurors were told to stay home on Monday. But it was business as usual for the lawyers. We made our way to the courthouse and waited for word from the judge. Would he approve the plea agreement? Or would the trial continue?

Finally, the judge called us to chambers: he would approve. Within minutes, the accused had entered a plea of guilty and the trial was over. Soon, the judge issued a written statement to jurors criticizing the Attorney General's decision.

The trial's outcome left us with mixed emotions. The facts were hotly contested and the legal issues were novel. From an intellectual standpoint, we wanted to see a verdict. But with the death penalty on the table, the risks of continuing to litigate were simply too high. In these challenging cases, a settlement that saves the accused from execution is sometimes the best result possible.