MIAMI — A 16-year-old stepbrother of Anna Kepner pleaded not guilty Tuesday in a Miami federal court filing to federal charges including murder and aggravated sexual abuse in connection with her death. The filing, which identified the defendant by the initials T.H., also waived his appearance at an arraignment scheduled for Wednesday.

T.H.'s defense attorney said via email Tuesday, "He will simply be arraigned tomorrow." Federal prosecutors confirmed the hearing was still expected to take place, which would have been T.H.'s first court appearance since he was indicted earlier this month.

T.H. was indicted April 13 on federal charges, including murder and aggravated sexual abuse, in connection with the death of Anna Kepner, 18. According to a news release from the U.S. Attorney's Office for the Southern District of Florida, T.H. sexually assaulted Kepner before killing her. The case was transferred to adult prosecution and unsealed on April 10.

Kepner died on the Carnival Horizon cruise ship on Nov. 7 while on vacation with her family. The cruise returned to the Port of Miami the next day as planned. The Miami-Dade Medical Examiner's Office determined her cause of death was mechanical asphyxiation. The FBI has been leading the investigation because the death occurred in international waters.

Court documents related to a prior divorce and ongoing custody battle involving T.H.'s parents indicate officials had been looking into T.H. in connection with the death since November. Those documents state that T.H. and his mother, Shauntel Hudson Kepner, were on the cruise with Anna Kepner, along with Kepner's father, at least one of her biological siblings, another of Shauntel Hudson Kepner's minor children, and Kepner's grandparents. According to an attorney, Anna Kepner was sharing a room with her stepbrother on the trip. Anna Kepner's father and T.H.'s mother were married in December 2024.

Shauntel Hudson Kepner said in a prior court appearance that her son was hospitalized shortly after the ship returned to Miami on Nov. 8 and was in counseling following his release. Since his arrest in February, T.H. has been staying with and in the care of an uncle, prosecutors said. In a court document filed Monday, attorneys for T.H. opposed the government's effort to revoke his pretrial release.

"Justice needs to be served," said Chris Kepner, Anna Kepner's father and T.H.'s stepfather, who has said he believes T.H. should be in custody.

Anna Kepner's obituary described her as a high school senior and cheerleader from central Florida. Kepner was 18 at the time of her death on Nov. 7.