Woman killed on cruise ship; husband detained, FBI says

(CNN) - A Los Angeles-area man was in police custody Thursday in connection with the killing of his wife while on a cruise along the Mexican coast, FBI spokesman Darrell Foxworth told CNN.

Shirley McGill, 55, was found dead in her cabin on the Carnival Elation on Tuesday as the ship, after a five-day cruise to Cabo San Lucas, was heading back to its origination point of San Diego, California, authorities said.

Robert McGill, who is in his mid-50s, is facing a charge of murder on the high seas, FBI Special Agent in Charge Keith Slotter told CNN sister network HLN. The McGills were from Winnetka, a suburb of Los Angeles, authorities said.

The FBI and the Carnival cruise line said that a domestic dispute Tuesday night resulted in the woman's death, but did not elaborate on how she was killed. The FBI said the cause of death would be determined through autopsy.