Anna Kepner,18, who was found dead aboard the cruise ship Carnival Horizon on November 8. In a major development in the case, her 16-year-old stepbrother is being investigated in connection with the probe, reports citing court filings stated Tuesday.

As a result, the focus has turned to the family: her father, Christopher Kepner, stepmother Shauntel Hudson, and her two stepbrothers.
Anna Kepner family
Anna Kepner was the only daughter of his father, Chrisopher Kepner, from his previous marriage. Chrisopher Kepner later married Shauntel Hudson, who has two son from her previous relationship. Christopher Kepner and Shauntel Hudson lived with their three children - Anna and her two stepbrothers, in Titusville, Florida.
Christopher Kepner and Shauntel Hudson, and their three children, were on the Carnival Cruise Line ship for a trip to the Caribbean during which Anna Kepner was found dead. Reports identified one of the stepbrother as a 16-year-old, while details on the other are not public.
In a tribute after Anna Kepner's death, the family described her as “a bright, kind-hearted young woman whose presence brought warmth and energy” and recalled her as someone who “if you were sad, she'd make you laugh,” PEOPLE reported.
The family has asked friends and mourners to wear bright colors, especially Anna's favorite color, blue, to her memorial to honor her radiant personality and love for life, per the New York Post.
The family was travelling on a cruise
{{/usCountry}}The family has asked friends and mourners to wear bright colors, especially Anna's favorite color, blue, to her memorial to honor her radiant personality and love for life, per the New York Post.
The family was travelling on a cruise
{{/usCountry}}Anna was travelling on the Carnival with her father, stepmother, and three stepsiblings when the tragedy occurred.
Court filings in an unrelated family-court case disclose that one of Anna's stepsiblings, a minor, is now being considered a possible suspect under investigation by the Federal Bureau of Investigation (FBI).
Read more: Anna Kepner update: Florida teen's father breaks silence, blasts FBI over probe; 'no idea what...'
According to ABC News, Anna's stepmother, Shauntel Hudson, has asked the court to delay her custody hearing, citing that one of her minor children might face criminal charges.
The stepsibling has been released from custody.
Read more: Anna Kepner's stepbrother may face charges as alleged ‘uncle’ makes big claim
Investigators are reviewing surveillance footage, swipe-card access logs on the ship, cellphone records and interviewing family members, crew and other passengers.
The FBI has jurisdiction over the case because Anna is a U.S. citizen and the incident occurred in international waters.
According to reports, Anna told her father and stepmother she was feeling unwell the night before she died and returned to her cabin. The next morning, she was missing from a family breakfast.
A housekeeper discovered her body under a bed in the cabin, “wrapped in a blanket and covered by life vests,” aboard the Carnival Horizon while returning to PortMiami.
The Miami-Dade Medical Examiner determined her time of death as 11:17 a.m. on November 7 but has not yet released a cause or manner of death.