He was the first to board the ship, fired a shot at the captain, helped steal $30,000 in cash from a safe, and bragged about hijacking ships in the past, authorities said.
But the swagger authorities say the 18-year-old displayed on the ship had evaporated by the time to face a piracy charge that carries a mandatory life prison sentence. He is the first pirate charged in the United States in more than a century.
The tough demeanor he was alleged to have shown on the high seas dissolved into audible sobs as his lawyers notified the court that they had spoken to his family in Somalia. When the judge asked him if he understood that court-appointed lawyers would represent him, the teenager responded through a translator: "I understand. I don't have any money." He still had a tattered white bandage on his left hand that resulted from getting stabbed by a sailor during the skirmish.
His defense lawyers portrayed Muse as a frightened kid and not the violent pirate depicted by prosecutors. They believe he is 15 years old and should be given greater protections under international law because of his age and the circumstances of his situation, and predicted he would be exonerated.
"As you can tell, he's extremely young, injured and terrified," lawyer Deirdre von Dornum said.
Muse was charged with several counts, including piracy under the law of nations. That charge carries a mandatory penalty of life in prison.
The decision by the federal government to bring Muse to justice here has thrust the teenager into international spotlight and has raised legal questions about whether the U.S. is going too far in trying to make an example of someone so young.
Muse's age was called into question by differing accounts, but the judge who heard arguments about the issue ruled Tuesday that he can be tried as an adult. The government says he's 18.
On Wednesday, his mother, Adar Abdirahman Hassan, reiterated that her son is 16.
"I plead with the American judges not to commit an injustice against Abdiwali and hand down an unfair verdict on my son," Hassan said from her home in Galkayo town.
Muse appeared in court as investigators released new details of the hijacking in a criminal complaint against the defendant, the oldest of 12 children and the son of parents who scraped together a few dollars a day in Somalia selling milk and tending to a small herd of camels, cows and goats.
The complaint by FBI agent Steven E. Sorrells provided dramatic new details about the seizure of the ship and what transpired before three pirates were shot by U.S. snipers and Muse was captured.
Sorrells said that the ship's captain, Richard Phillips, told him he fired multiple warning flares at the pirate boat to try to chase them away as they approached in the middle of the night April 8.
The agent said Muse was the first pirate to board the boat when he climbed up a portable ladder, armed with a gun, as the boat was about 280 miles off the coast of Somalia.
"From the deck of the Maersk Alabama, Muse fired his gun at the captain who was still in the bridge," Sorrells said. The bridge is an enclosed room in the rear of the ship that provides a view of the deck and the surrounding waters.
The agent said Muse entered the room, told the captain to stop the ship and "conducted himself as the leader of the pirates."
After the other pirates boarded the boat, three of them accompanied the captain to a safe where he took out about $30,000 in cash, which was then taken by the pirates, the agent said.
Sorrells said the pirates held Phillips on a lifeboat for four days, with Muse telling the captain at one point that he had hijacked other ships before.
But Muse wasn't the most savvy pirate.
Investigators said Muse was tricked into leaving his weapon behind with fellow pirates when he went to hunt for other crew members. A crew member apparently told Muse the crew would be afraid to surrender if he was armed.
With Muse searching the boat with a flashlight after the power was shut off by a crew member, one of them hid briefly and then tackled him, the agent said. Another crew member then helped tie Muse's hands with wire and took him to a room where other crew members were, Sorrells said. Later, Muse was freed when he and the other pirates left the boat with the captain to begin their four days on the lifeboat.
After the captain tried to escape by jumping in the water, the pirates fired a gun at him and later tied him up and hit him, Sorrells said.
The crew member who stabbed Muse said Tuesday that the teenager counted himself lucky to raid a U.S. ship and carried himself as the leader of the pirate gang.
"He was surprised he was on a U.S. ship. He kept asking, `You all come from America?' Then he claps and cheers and smiles. He caught himself a big fish. He can't believe it," crewmember ATM "Zahid" Reza said. Muse planned to demand at least $3 million, Reza said.
He said Muse told him it was his dream to come to America. "His dreams come true, but he comes to the U.S. not as a visitor, but as a prisoner," Reza said.
, with his parents in Somalia insisting he was tricked into getting involved in piracy. His mother said he was "wise beyond his years" - a child who ignored other boys his age who tried to tease him and got lost in books instead.
"The last time I saw him, he was in his school uniform," the teen's mother, Adar Abdirahman Hassan, 40, told The Associated Press by telephone Tuesday from her home in Galkayo. "He was brainwashed. People who are older than him outwitted him, people who are older than him duped him."
Omar Jamal, executive director of Somali Justice Advocacy Center in Minneapolis, said his Somali immigrant organization made contact with family members of the pirates during the hostage standoff.
Muse's family members "don't have any money. The father has some camels and cows and goats outside the city. ... The father goes outside with the livestock and comes home at night. Father said they don't have any money, they are broke," Jamal said.
Muse's mother sells milk at a small market every day, saving around $6 every month for school fees for her oldest son. She pays $15 a month in rent.
Jamal said his organization was working to get a lawyer for Muse and to find if he has medical or mental problems.
"What we have is a confused teenager, overnight thrown into the highest level of the criminal justice system in the United States out of a country where there's no law at all," Jamal said.
Alfred P. Rubin, a professor of international law at Tufts University who wrote a book on piracy, said there had not been a major pirate prosecution in the United States since 1885, when the American ship Ambrose Light was attacked by pirates.
Reza, the crew member who stabbed Muse, plans to testify against him in his trial, but hopes not to see him.
"No, I don't want to see him. Not at all. I hate his face. I could have died," Reza said.