Man Accused of Killing Wife on Cruise to Mexico

A man accused of killing his wife onboard a Carnival cruise sailing from Mexico to San Diego has has been charged with murder by federal authorities, according the Associated Press.

Robert McGill of Los Angeles allegedly killed his wife, Shirley, Tuesday in their cabin during a domestic dispute on the final leg of five-night cruise.

"The husband was taken into custody aboard the vessel and all appropriate authorities, including the FBI and U.S. Coast Guard, were notified," Carnival said in a statement.

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Crew members found the body of the 55-year-old woman when they entered the cabin and McGill was placed in the ship's brig for the duration of the cruise, according to the Associated Press.

When the ship returned to San Diego at 6:30 this morning, federal agents boarded and began their investigation. The San Diego County medical examiner arrived and removed the Shirley McGill's body about three hours later.

Carnival says the incident occurred on the Carnival Elation, a 2,052-passenger ship based in San Diego. The ship departed July 11 on a five-day cruise to Cabo San Lucas, Mexico.

According to the company's Web site, the Elation is a member of the fleet's mid-sized Fantasy Class and is registered in Panama.

"Our thoughts and prayers go out to the victim's family," Carnival said in the statement. "Carnival's CareTeam is offering assistance."

Carnival, like many cruise lines, said it does not keep statistics of crimes aboard its ships. Congress is considering a bill that would require the companies to keep records of crimes onboard and train crew members to investigate crime scenes.

"There is no particular criminal law at sea," said New York State Juedge Thomas Dickerson, author of "Travel Law." "The captain is in charge and his job is to protect the passengers and crew. That means incarcerating the suspect in brig and delivering him to the authorities wherever he makes port."

Some 20 FBI agents were taken to the ship while at sea Wednesday night on a U.S. Coast Guard Cutter. They spent the night interviewing the suspect and 30 to 40 potential witnesses.

Once the ship arrived in California, U.S. and state authorities had jurisdiction in the case, Dickerson said.

Maritime law also requires that all crimes aboard cruise ships be reported to the country where the ship is flagged -- Greece, Panama and the Bahamas being the three most common flag states. In the United States, cruise lines have an agreement with the FBI and the Coast Guard to report crimes in U.S. waters or involving U.S. citizens.

Former U.S. Rep. Christopher Shays, a Connecticut Republican, who while in politics advocated for cruise lines to report crimes, told in January that cruise ships are "the place to commit the perfect crime."

"You don't need a major weapon, and your evidence disappears," he said. "They say they're a miniature city, but they don't have anyone on board who is capable of investigating a crime."

The Associated Press and ABC News's Sarah Netter contributed to this report.