A Nigerian man pleaded guilty Wednesday to trying to bring down a jetliner with a bomb in his underwear, defiantly telling a federal judge that he acted in retaliation for the killing of Muslims worldwide and referring to the failed explosive as a "blessed weapon."

Umar Farouk Abdulmutallab, who acknowledged working for al-Qaida and never denied the allegations, entered the plea against his attorney's advice on the second day of his trial. He stands to get a mandatory life sentence for the 2009 attack that aimed to kill nearly 300 people on Christmas Day in the skies above Detroit.

Abdulmutallab calmly answered the judge's questions and read a political statement warning that if the United States continues "to persist and promote the blasphemy of Muhammad and the prophets," it risks "a great calamity ... through the hands of the mujahedeen soon."

"If you laugh at us now, we will laugh at you later on the day of judgment," he said.

Abdulmutallab suggested more than a year ago that he wanted to plead guilty but never did. He dropped his four-person, publicly financed defense team in favor of representing himself with help from a prominent local lawyer appointed by the court, Anthony Chambers.

In an interview, Chambers said Abdulmutallab privately renewed his interest in a guilty plea Tuesday before the start of the trial. But it did not happen immediately because the defendant was not prepared to go through the lengthy required question-and-answer session with the judge.

When the two met again Wednesday morning, Abdulmutallab was ready, Chambers said.

Prosecutors were aware of a possible plea, but there were no negotiations. Abdulmutallab had "no interest" in speaking to prosecutors, Chambers said, and was unlikely to get any benefit at this stage of the case.

"It was too late. We were ready to go," U.S. Attorney Barbara McQuade said.

Chambers wanted to go to trial to raise doubts about just how powerful the explosive was. And if Abdulmutallab were convicted, there was also a possible appeal involving the lack of a Miranda warning before a crucial FBI interview.

"I know he prayed about it and came to what he believed was the right decision," Chambers said. "I don't think there was anything done (at trial) that made him say, 'This is a done deal. I have to take a plea.' It was a personal decision."

Passenger Lori Haskell of Newport, Mich., watched the plea by video from a room near the court. She called Abdulmutallab's statement "chilling" but not surprising.

"I'm just really relieved that it's done with," she said.

The Amsterdam-to-Detroit flight was just moments from landing when Abdulmutallab tried to detonate the bomb in his pants. It failed to go off, but his clothes caught fire, and passengers jumped on him when they saw smoke and flame.

The evidence was stacked high.

The government said Abdulmutallab willingly explained the plot twice, first to U.S. border officers who took him off the plane and then in more detail to FBI agents who interviewed him at a hospital after he was treated for burns to his groin.

There were also photos of his scorched shorts, video of Abdulmutallab explaining his suicide mission before departing for the U.S. and scores of passengers who could have been called as eyewitnesses.

Attorney General Eric Holder said the plea "removes any doubt that our courts are one of the most effective tools we have to fight terrorism," referring to a long-running debate over whether suspects such as Abdulmutallab should be tried in civilian or military courtrooms.

"We will let results, not rhetoric, guide our actions," Holder said.

Dimitrios Bessis of Harrison County, Ga., sat two rows behind Abdulmutallab on Northwest Airlines Flight 253 and used his hat to beat out the flames. He said his trip to Detroit to serve as a potential witness was his first plane ride since the attempted attack.

"He put terror in children's eyes, in mother's hearts," Bessis said. "I've seen men freeze from shock on the plane. It was a horrible experience. I have nightmares from it."

A woman who sat six rows in front of Abdulmutallab on the plane, said the guilty plea provided her with "relief."

"It was disheartening and sickening, however, to listen to Abdulmutallab explain why he feels his actions were justified," Hebba Aref, a Detroit-area native, wrote in an email to The Associated Press.

"As a Muslim myself, I know that he has a completely erroneous and distorted interpretation of the Quran."

Abdulmutallab, the well-educated son of a wealthy banker, told investigators he trained in Yemen, which is home base for Al-Qaida in the Arabian Peninsula. He said he targeted a U.S.-bound flight at the urging of Anwar al-Awlaki, a radical, American-born Muslim cleric recently killed by the U.S. military in Yemen.

In court, he sometimes appeared agitated, declaring that Osama bin Laden and al-Awlaki were still alive. He also objected to trial testimony from experts who would have discussed al-Qaida and martyrdom.

Abdulmutallab, who told the judge he is 25, pleaded guilty to all eight charges, including conspiracy to commit terrorism and attempted use of a weapon of mass destruction. He is scheduled to be sentenced Jan. 12.

When Assistant U.S. Attorney Jonathan Tukel asked if he was carrying a bomb, Abdulmutallab replied: "If you say so." He said he was "guilty of U.S. law but not in the Quran."

The case had lasting implications for security screening at American airports.

Abdulmutallab's ability to defeat security in Amsterdam contributed to the deployment of full-body scanners at U.S. airports. The Transportation Security Administration was using the scanners in some American cities at the time, but the attack accelerated their placement.

There are now nearly 500 devices nationwide.

Passenger Alain Ghonda of Silver Spring, Md., said he came to court Wednesday "to see the man who tried to kill me." He took some comfort in knowing Abdulmutallab would be locked up for many years.

"At least he will be going away for hopefully forever and not be able to harm other people," he said.


Associated Press writers David Runk and Jeff Karoub in Detroit and Matt Apuzzo in Washington contributed to this report.