NEW YORK - Abdiwali Abdiqadir Muse has admitted he's a modern-day pirate. The US government says he also had a sadistic streak.

While terrorizing merchant ships on the Indian Ocean, Muse regularly aimed "his gun at the head of a hostage and pulled the trigger, laughing when the gun did not fire," federal prosecutors wrote in court papers. "Muse derived joy from the suffering of victims."

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The prosecutors argued Muse's ruthlessness is one reason he should get nearly 34 years at sentencing Wednesday in a Manhattan courtroom. Defense attorneys have countered in their court papers that their client, who's from Somalia, is an impoverished and naive young man whose crimes were born of desperation.

"The temptations of piracy were overwhelming for (Muse)," they said in seeking the 27-year minimum sentence. "He had so little to lose."

Muse's involvement in a brazen high-seas attack on a US-flagged vessel and the dramatic rescue of the ship's kidnapped captain in 2009 made him an instant symbol of a 21st-century brand of piracy targeting shipping routes off the coast of Africa -- and of stepped-up efforts to punish offenders through 19th-century maritime laws.

Late last year, a Virginia jury found five other Somali men guilty of exchanging gunfire with a US Navy ship off the coast of Africa. Scholars called it the first piracy case to go to trial since 1861 during the Civil War, when a New York jury deadlocked on charges against 13 Southern privateers.

Aside from the novelty of his case, Muse became a curiosity because he defied swashbuckler stereotypes: The boyish, 5-foot-2 (1.57-meter) defendant has often looked bewildered in court and sometimes wept. Following his capture, his lawyers insisted he was 15 and should be tried as a juvenile; prosecutors convinced a judge he was at least 18.

In a guilty plea last year, Muse told a judge he was "very, very sorry about what we did."

Prosecutors branded Muse the ringleader of a band of armed pirates who commandeered at least three ships and kidnapped dozens of sailors. The last attack was on the Maersk Alabama on April 8, 2009, as it transported humanitarian supplies about 280 miles (450 kilometers) off the coast of Somalia, an impoverished East African nation of about 10 million people.

Muse was the first to board the 500-foot (150-meter) ship, firing his AK-47 assault rifle at the captain, Richard Phillips, prosecutors said. He ordered Phillips, of Underhill, Vermont, to halt the vessel and then held him hostage for several days on a sweltering, enclosed lifeboat that was soon shadowed by three US warships and a helicopter.

The English-speaking Muse taunted Phillips by threatening to "bury him in a shallow area of the ocean" and by telling his captive he "liked having hijacked an American ship and wanted to kill Americans," the government's court papers said.

The siege ended when Navy sharpshooters on the USS Bainbridge picked off the three pirates in a stunning nighttime operation, leaving Phillips untouched.

The defense has since claimed Muse was a low-level pirate who was following orders, and it accused the Navy of opening fire after he had negotiated Phillips' release. Defense lawyers also have stressed that their client comes from a troubled nation where piracy has become a multimillion-dollar business, despite a flotilla of international warships patrolling nearby waters.

Muse "would not be before the court for sentencing if not for the chaotic conditions prevalent in Somalia and the hunger and deprivation he has experienced in his young life," his lawyers wrote.

Prosecutors agreed it was likely Muse "endured an extremely difficult upbringing." But, they added, "so have millions of other citizens of Somalia."

"Unlike Muse, however," prosecutors said, "they have not resorted to preying on the defenseless and terrorizing the innocent -- time after time."