An 18-year-old Florida teen was found dead and hidden under a bed on a Carnival cruise ship — and now her 16-year-old stepbrother is facing charges in the case.

Federal prosecutors say the boy, identified as T.H., has been charged with sexually assaulting and murdering Anna Kepner while aboard the Carnival Horizon. The case was initially sealed because of his age, but a judge has ruled he will be prosecuted as an adult.

Anna’s body was discovered on November 7 by a cabin steward. According to authorities, she was wrapped in a blanket and concealed under a bed, with life jackets placed on top of her.

She had been sharing the room with two other teens, including the suspect.

An autopsy determined her cause of death was mechanical asphyxia, meaning she was suffocated by force.

The Carnival Horizon was traveling through the Caribbean at the time of the killing.

Investigators had focused on the stepbrother early on. Anna’s father, Chris Kepner, previously said the boy was the only person in the room when she died.

“I want him to face the consequences,” he said at the time, while acknowledging the investigation was still ongoing.

Family members have also pointed to conflicting claims about what happened that night. According to court records, the suspect’s mother told Anna’s father that the boy had no memory of the events surrounding her death.

Before the killing, there were no public signs of conflict between the teens. Anna’s mother, Shauntel Kepner, said the group chose to share a room together during the cruise because they were close.

“The three of them… are best friends,” she said in earlier testimony.

Anna, who was from Titusville, Florida, was a high school senior preparing to graduate this year. Family members say she had plans to attend college and had talked about becoming a cheerleader at the University of Georgia. She had also considered joining the military or working in law enforcement as a K9 officer.

The charges mark a major development in a case that has raised questions about safety and supervision aboard cruise ships. The investigation involved the FBI due to the crime taking place in international waters. The suspect remains in custody as the case moves forward in federal court. Authorities have not released additional details about what led up to the killing.