AP
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The death of a Florida teenager on a Carnival cruise ship earlier this month has been ruled a homicide, the latest development in the case that has drawn international attention and intense speculation on social media.
Anna Kepner’s cause of death was “mechanical asphyxiation,” according to a copy of her death certificate obtained by ABC News, which stated that the 18-year-old was “mechanically suffocated by other persons.”
Mechanical asphyxiation occurs when an object or physical force prevents someone from breathing, according to Central Florida Chief Medical Examiner Stephen Nelson, who is not involved in the case.
“In some way, shape or form, your airway has been cut off,” said Nelson, the former chairman of Florida’s Medical Examiner Commission.
Kepner, a high school cheerleader from Florida’s Space Coast who was set to graduate next year, was traveling on the Carnival Horizon ship with her father, stepmother, her stepmother’s two children and her grandparents.
The night before he was found dead, Kepner had spent time with his grandparents in the ship’s casino, his grandmother, Barbara Kepner, told ABC News.
Barbara Kepner recalled, “She said, ‘Meemaw, I love you guys. I’ll see you. … I’ll see you later.’ “After that we never saw him again.”
The next morning, a medical alert was issued over the ship’s broadcast system, which directed first responders to the room where Kepner was staying with two other teenagers, including a younger half-brother.
According to his grandmother, a room attendant found Kepner’s body “hidden under the bed”.
“I just screamed. I couldn’t stop screaming,” said Barbara Kepner.
Kepner’s death on the plane that left Miami has been shrouded in mystery because the FBI and the medical examiner’s office in South Florida have refused to release any information about the case for weeks.
The teen’s 16-year-old stepbrother has been identified as a suspect in her death, according to court documents filed by the teen’s parents.
The revelations — contained in petitions filed in the ongoing custody dispute — provide the clearest public indication that federal investigators are investigating a member of the victim’s own blended family.
As of Tuesday, the final autopsy report had not been released and the Miami-Dade County Medical Examiner’s Office did not respond to recent messages left by the AP.
According to the medical examiner’s office, Kepner’s time of death was 11:17 a.m. on November 7. The ship returned to PortMiami on 8 November as scheduled.
According to the itinerary posted on the company’s website, Carnival Horizon sails the western Caribbean with stops in Cozumel, Grand Cayman, Montego Bay and Ocho Rios.
Nelson, the medical examiner, said he considered Kepner’s death “highly, highly suspicious” and said reports that his body had been hidden supported the conclusion of murder.
“The concealment part alone is very disturbing,” Nelson said. He added, “If (the drug test) comes back clean and he didn’t overdose, you know it would obviously be a murder.”
Kepner’s family has been told that preliminary information indicates there were no signs of sexual assault and that Anna did not have drugs or alcohol in her system, ABC News reports.
Nelson, who was not briefed on the case, said there were a number of deaths that could be defined as suffocation, including drowning, strangulation and hanging.
The language stating that Kepner was “mechanically suffocated by other persons” is fairly standard language, Nelson said, and is an admission that Kepner was sharing a room with other people.
“It will be up to law enforcement to limit what role, if any, each of the other people in the room played,” Nelson said.
Determining who has authority over a criminal investigation can be complicated because cruise ships are registered in a single country but often travel through many other countries while carrying thousands of passengers and crew members from around the world, the FBI said in a document that outlines the challenges of investigating crimes on cruise ships.
The agency says cooperation is key to any investigation on the high seas where U.S. law, international law and the laws of other countries may be involved.
The nature of a floating crime scene can also make investigation challenging as it may leave a small window of time for investigation before the ship departs on its next voyage.
“You have a very short time to do your best to solve this case or gather all the evidence you need to solve this case and then your crime scene will be over,” FBI Special Agent Matt Parker said in the FBI document.
A federal law, the Cruise Vessel Security and Safety Act, requires that most cruise ships operating from U.S. ports report certain types of serious crime to the FBI. During the latest publicly available period – July 1, 2025, to September 30, 2025 – Carnival Cruise Line reported 9 cases of “sexual assault-rape” and 3 cases of “sexual harassment.”
In 2023, the FBI received 180 reports of alleged criminal activity on cruise ships, ranging from theft to sexual and physical assaults to missing persons cases, the agency said.
All seven cruise companies that filed reports during the quarter reported at least one case of sexual harassment. According to US Department of Transportation data, no suspicious deaths were reported during this period.
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