A Florida teenager, Timothy Hudson, has been ordered detained while awaiting trial for the alleged sexual assault and murder of his 18-year-old stepsister, Anna Kepner, on a Carnival cruise ship last year.

Hudson was originally charged as a juvenile but later transferred to adult court, where he now faces charges that could result in a life sentence.

The court ruled he must remain in custody, citing the seriousness of the alleged crimes and the danger he poses, and he will undergo a mental health evaluation while detained.

Prosecutors say Kepner was found asphyxiated in the ship cabin she shared with Hudson, and her death was ruled a homicide, NBC 6 Miami has reported.

Hudson has pleaded not guilty, and his trial is scheduled to begin in September.