(CBS) Monday's announcement of a plea bargain in the John Walker Lindh case was no surprise to the White House, which was told Thursday that negotiations were in progress on a proposed deal.

But when the so-called "American Taliban" actually pleaded guilty in open court in Alexandria, Va., Monday, no one was more shocked than the family of Johnny "Mike" Spann, the CIA agent who was killed last November in the Taliban and al Qaeda uprising at the prison fortress where Lindh was being held.

"He's a murderer. There's no other way you can whitewash it," said Spann's father, Johnny, adding that he feels his son was let down by his commander-in-chief. "I just don't feel like they did justice - to not only Mike, but to all the people who had died in terrorism or 9/11."

Spann had interrogated Lindh at the fortress and while Lindh was never directly accused in the death of the CIA agent, his mother considers Lindh to be one of her son's killers because he did not warn him about explosives at the prison.

The plea bargain struck in late night negotiations on Sunday means the 21-year-old American who studied Islam and joined the Taliban army will escape the life sentence he could have faced had he been convicted at trial of charges including conspiring to kill Americans.

Asked if the plea bargain is fair, Spann's mother replied: "Of course not, to Mike's family. I'm sure it is, to John Walker (Lindh)'s family, but we don't think it is to us, of course. As Mike's mom, I would like for Mike to have had 20 years to live."

Lindh will be required to serve 20 years in prison - getting out of jail at the relatively young age of 41 - and cooperate with government investigators hoping to learn more about the Taliban and al Qaeda. He may also be asked to testify at future trials of other suspects.

"I provided my services as a soldier to the Taliban last year from about August to November," Lindh told U.S. District Judge T.S. Ellis III in court Monday, recounting the two crimes to which he pleaded guilty. "During the course of doing so I carried a rifle and two grenades. And I did so knowingly and willingly."

In accepting the plea, prosecutors foreclosed the chance for the public to see evidence in the first major trial scheduled from the war on terrorism.

U.S. Attorney Paul McNulty said prosecutors had a strong case against Lindh but wanted to reserve "limited and very vital resources" for other terrorism cases.

"This is a tough sentence. This is an appropriate punishment and this case proves that the criminal justice system can be an effective tool in the fight against terrorism," McNulty said.

"I don't think it's a victory to my son, who gave his life," said Gail Spann. "But we do live in a country where we have to abide by our justice system and I respect our justice system, as did my son."

Chief defense lawyer James Brosnahan said Lindh joined the Taliban because he was a devout Muslim. He never fired his rifle and never intended to hurt Americans, the lawyer said.

"This is not Rambo we're talking about here," Brosnahan said.

Lindh's mother, Marilyn Walker, broke down outside the courthouse as she called him an "honest, kind, humble and a loving son."

"Never once did John say anything against the United States," said Frank Lindh, the defendant's father, adding that he is "proud to have him as a son."

A friend of the family, Bill Jones, was critical of Lindh's treatment by the government.

"I had a chill right down the middle of my stomach," said Jones, on hearing the news of the plea bargain. "His only guilt as far as I'm concerned is that he became a fundamentalist Muslim."

Lindh was set to be tried Aug. 26, and now will be sentenced Oct. 4.

Monday's events leaves Zacarias Moussaoui, the Frenchman charged with conspiring with the Sept. 11 hijackers, as the lone defendant awaiting trial on terrorism charges. His trial is to begin at the end of September.

Lindh, 21, entered the courtroom wearing a green prison jumpsuit and offered a quick smile to his parents, older brother and younger sister sitting in the second row.

The judge had planned to hold hearings this week on whether Lindh's statements to investigators and the news media in Afghanistan should be kept out of his trial.

"I plead guilty," Lindh told Ellis as he entered his plea to one count of supplying services to the Taliban, Afghanistan's now-ousted strict Muslim rulers. To the charge of carrying explosives during commission of a felony, Lindh said, "I plead guilty, sir."

Each side had its reasons for the deal.

A government official, speaking on condition of anonymity, said the Bush administration was concerned that if the case went to trial, intelligence officers would have to appear and al-Qaida and Taliban detainees held by the United States in Cuba might be allowed to testify for the defense.

Defense lawyer Tony West said Lindh's attorneys believed they could have won on eight terrorism-related counts but would have had difficulty defending against charges that he helped the Taliban and used firearms during violent crimes.

Lindh, who had accused the military of keeping him imprisoned in Afghanistan under horrible conditions, dropped the claim and acknowledged he was not intentionally mistreated.

Under federal law, Lindh could earn up to three years off his sentence for good behavior, but a judge would have to approve any reduction, Justice Department officials said. Lindh requested imprisonment in California near his family and the government had no opposition, but the decision is up to the U.S. Bureau of Prisons.

Lindh came to public attention in December when he was captured with other Taliban prisoners during the war with U.S. military. Bearded and sporting long hair, he gave a hospital bedside interview to CNN in which he professed support for the Taliban.

Government officials who reconstructed his path from a teen-age convert to Islam in San Francisco's suburbs to a foot soldier in Afghanistan alleged he trained at an al Qaeda camp and once met Osama bin Laden.

By the time he was returned to the United States, Lindh had short hair and his lawyers and family worked hard to portray him as an average American who loved his country. Outside the courthouse, his father said he was thankful the government dropped the more serious terrorism charges.

Before accepting the plea, Ellis asked Lindh if he was willing to forgo a trial.

"Yes, sir," Lindh responded.

The judge then asked Lindh a series of standard questions about his background.

"I attended some college in California as well as Yemen," Lindh explained.

The judge asked him to speak louder. "Do you feel as though you can make a decision about your future today?" Ellis asked.

"Yes," responded Lindh.

As part of the agreement, any profits Lindh might someday make from telling his story will be turned over to the government.