NEW YORK (AP) – When U.S. prosecutors brought piracy charges against a teenager from Somalia, they dusted off a law that has been on the books since George Washington was president and used only sparingly since then.

The law’s obscurity, the lack of recent precedent and murky definitions of what constitutes piracy could present challenges to law enforcement. But prosecutors also boosted their case with more common nonpiracy charges that could lead to a long prison sentence, even if the piracy count doesn’t stick.

The government “threw pretty much everything they had at this guy because I think they wanted to hedge their bets,” said Eugene Kontorovich, a professor at Northwestern University Law School.

In a criminal complaint, prosecutors depicted Abdiwali Abdiqadir Muse as the brazen ringleader of a band of four pirates who bullied 20 crew members of an American-flagged cargo ship, fired a shot at the captain and boasted of hijacking other ships. They said he executed the maneuver like a veteran pirate, stealing $30,000 from a safe and demanding that the crew give him the phone number of the ship’s owner.

Muse’s family says he is an impressionable minor who fell under the sway of older pirates and is being unfairly targeted by the U.S. government. Muse appeared bewildered, if not scared, in his first court appearance on Tuesday, breaking down in tears as lawyers told the judge that they had spoken to his father.

There are varying accounts of his age – his lawyers say 15, his parents say 16 and the government says at least 18. The judge heard testimony from his father via telephone from Somalia and from government officials Tuesday before determining Muse should be tried as an adult.

The top count against Muse accuses him of piracy under the law of nations, a charge not used regularly since the 1800s. It carries a mandatory life sentence.

The other charges against him – discharging a firearm, conspiring to commit hostage taking and brandishing a firearm – could be found in drug, kidnapping and conspiracy cases throughout federal courthouses in the United States. They also offer potential penalties up to life in prison.

The government also set up a scenario in which they could eventually drop the piracy count in a plea bargain that would give Muse a chance to dodge a life sentence. That could be necessary if legal questions are raised by the piracy statute.

Michael Passman, a Chicago author of articles on piracy and the law, said piracy has a range of definitions, depending on which set of laws are interpreted. U.S. statutes define it one way. International laws define it a different way. The “law of nations” cited in the charges can draw on any number of legal parameters.

“That is something the court is going to have to confront,” he said. But “recent practice suggests that the civilized world knows what the definition of piracy is under the law of nations.”

Kontorovich said the piracy statute filed against Muse has been around since 1791, but hasn’t really been used since 1885. The law carried a mandatory death penalty until the 1900s and was last rewritten in 1948, he said.

He noted prosecutors had also charged Muse with conspiracy to seize a ship by force, a count used only once since it was written to combat terrorism after the 1985 hijacking of the Italian cruise ship Achille Lauro.

He said that law was written because piracy statutes could not be used against the hijackers who killed 69-year-old New Yorker Leon Klinghoffer during the ship’s hijacking, because the piracy statutes required that two vessels be involved; the Achille Lauro hijackers had boarded the vessel and posed as passengers.

Kontorovich has written an article to be published by the California Law Review about the difficulties of prosecuting pirates and terrorists.

In it, he writes that nations have generally released pirates because it is difficult to detain or successfully prosecute them. He said hundreds of pirates are routinely released after they are caught. The difference between those cases and the current one is that an American-flagged vessel was attacked.

“We don’t want a Guantanamo of the seas,” he said. “What are we going to do with all these guys – the cost of detaining them, complicated trials. What if they ask for prisoner of war rights? They would play the Guantanamo playbook from page one.”

Meanwhile, a Minnesota group is under fire for helping Muse’s family navigate the American legal system.

A Minnesota Republican lawmaker, Rep. Marty Seifert, said he wants to ensure that no taxpayer dollars or state grants go to groups supporting pirates, such as the one run by Omar Jamal. Jamal, director of the nonprofit Somali Justice Advocacy Center, said Muse’s parents asked for his help and that he is not weighing in on Muse’s guilt or innocence.

“We act as an intermediary between the system and the community,” Jamal said. “In this case we are trying to help the family understand what’s going on here.”