Abdulmutallab (Muhammad Salisu Rabiu / Associated Press)
Detroit -- Former classmates nicknamed him "the Pope," but Umar Farouk Abdulmutallab's own father had recently warned authorities of his radical religious views.
The product of a well-to-do banking family, Abdulmutallab attended elite schools and led a privileged life.
But in recent months, he became estranged from his family, prompting his father to alert U.S. officials of his son's growing interest in extremist Islam.
It appears his concerning behavior boiled over Friday, when the Nigerian native allegedly attempted to detonate an explosive that could have wiped out nearly 300 passengers and crew members on a Northwest Airlines jet as it approached Detroit Metropolitan Airport on Christmas Day.
On Sunday, the 23-year-old was relocated from the Ann Arbor hospital where he was being treated for burns to the federal prison at Milan.
He's facing up to 20 years in prison on felony charges of attempting to destroy an aircraft and placing a destructive device aboard an aircraft.
A 2 p.m. hearing is scheduled for today in front of U.S. District Judge Paul D. Borman, when prosecutors are expected to request permission to take a DNA sample from the defendant. But it was not clear Sunday whether today's hearing would go ahead, and Abdulmutallab was not expected to attend.
Miriam Siefer, the head of the Federal Defender Office in Detroit who is representing Abdulmutallab, at least temporarily, said, "We're researching their request (for a DNA sample) right now to see if there is a legal basis."
A search warrant seeking the sample remains sealed. Siefer, like federal officials, said she could not comment on why the sample is sought.
Abdulmutallab was said to be calm and smiling as he was formally charged Saturday in a board room at the University of Michigan Medical Center.
According to a criminal complaint, Abdulmutallab attempted to detonate explosive materials hidden under his clothing. Passengers and flight crew restrained him and put out a small fire he created.
Abdulmutallab could face more serious charges if he is indicted by a grand jury, interim U.S. Attorney Terrence Berg confirmed Sunday.
Shoe bomber Richard Reid was initially charged in a complaint filed in federal court in Massachusetts in 2001 with interfering with an airline flight crew, also a 20-year felony.
But Reid -- now serving a life sentence -- was indicted in early 2002 by a federal grand jury on charges that included attempted murder and attempted use of a weapon of mass destruction.
The first time Abdulmutallab is expected to appear in federal court in Detroit is for a hearing Jan. 8, at which federal prosecutors will seek a judge's order keeping him locked up pending trial. His attorneys may seek bail.
Prosecutors say Abdulmutallab -- who has no known ties to the Detroit area -- is considered both a flight risk and a danger to the public. Those are the two grounds on which the government may seek to detain him pending trial.
The son of an affluent banker, Abdulmutallab attended the British International School in West Africa and University College London to study engineering.
University College London, in a statement, said that a student named Umar Farouk Abdulmutallab had enrolled in mechanical engineering courses between September 2005 and June 2008. But they could not confirm he was the same individual apprehended in Detroit.
Once called "the Pope" by classmates as a sign of respect for his admirable religious beliefs, Abdulmutallab is described by former chums as a straight-laced kid who was "studious" and "good-looking," according to The Independent newspaper. His father, Alhaji Umaru Mutallab, formerly served as chairman of the First Bank of Nigeria, and his mother's family is originally from Yemen, according to news accounts in Nigerian newspapers.
Investigators are examining how Abdulmutallab apparently rebelled against his privileged upbringing to pursue an extremist goal.
Abdulmutallab allegedly began preaching to fellow students about Islam, according to a report in ThisDay, a Nigerian newspaper.
ThisDay reported that more recently, Abdulmutallab had moved to Dubai in the United Arab Emirates and told his family that he no longer wanted to associate with them.
The New York Times and Associated Press contributed to this report.