The man later told an acquaintance who later walked into the couple's blood-splattered room that he did it because she laughed at him, the FBI said in documents released on Thursday.
According to The Telegraph, Kenneth Manzanares was charged with murder after he was found with blood on his hands and clothes and blood spread throughout the cabin on the Princess Cruises ship on Tuesday night, according to a criminal complaint by FBI Special Agent Michael L. Watson.
Kristy Manzanares, 39, had a severe head wound, but authorities have declined to release other details in the case, including how many people were traveling with the couple on the 3,400-passenger Emerald Princess that left Sunday from Seattle.
A man and others went into the room before medical workers and security officers had arrived and saw the woman on the floor covered in blood, according to court documents.
The man asked Manzanares what happened, and the suspect said, "She would not stop laughing at me."
Manzanares then grabbed his wife's body and tried to drag her to the balcony, but the man stopped him, Watson wrote. A ship security officer handcuffed Manzanares in a nearby cabin.
While the FBI searched him, he spontaneously said, "My life is over."
Manzanares, 39, was scheduled to appear in federal court by videoconference from Alaska's capital city of Juneau later Thursday. He has no criminal history, according to online Utah court records.
"We conducted approximately 200 interviews of passengers and crew members," Marlin Ritzman, FBI special agent in charge of the Alaska bureau, told reporters.
The ship was diverted to Juneau because of the investigation, which the FBI is leading because the death occurred in U.S. waters.
The ship docked Wednesday morning, and passengers were kept on board for hours before the cruise departed late that night for the southeast Alaska town of Skagway.
Princess Cruises said in a statement Thursday that passengers will receive $150 onboard credit because of the effect on their vacations.
"You feel sorry for the family, but a lot of people had to wait," said Lloyd Barrows, a passenger from Alberta, Canada.