MIAMI — The stepbrother of Anna Kepner, who was found dead on a Carnival cruise ship last year, has pleaded not guilty to federal charges in connection with her death.

The plea was made in a Tuesday court filing that also waives the defendant's appearance at his arraignment, scheduled for Wednesday in Miami federal court, according to the filing.

The Wednesday court proceeding took less than 5 minutes, during which the judge accepted the plea.

Since his arrest in February, the defendant has been staying with, and has been in the care of, an uncle, prosecutors have said.

In a court document filed Monday, attorneys for the 16-year-old defendant — identified as T.H. — opposed the government's effort to revoke his pretrial release.

An appearance in court Wednesday would have been his first since he was indicted on federal charges in connection with his stepsister's death earlier this month.

Kepner, 18, died on the Carnival Horizon cruise ship on Nov. 7 while she was on vacation with her family. The cruise returned to the Port of Miami the next day, as was planned, Carnival said in a statement at the time.

T.H. was indicted April 13 on federal charges, including murder and aggravated sexual abuse, in connection with Kepner's death. In a news release, the U.S. Attorney’s Office for the Southern District of Florida said T.H. sexually assaulted Kepner before killing her but did not offer details about the alleged assault.

The Miami-Dade Medical Examiner’s Office determined Kepner’s cause of death was “mechanical asphyxiation.”

The case was transferred to adult prosecution and unsealed on April 10.

The FBI has been leading the investigation into Kepner's death because it occurred in international waters.

Officials had been looking into the 16-year-old in connection with Kepner's death since November, according to court documents related to his parents' prior divorce and ongoing custody battle, which also state that he and his mother, Shauntel Hudson Kepner, were on the cruise with Kepner.

Kepner's father and at least one one of her biological siblings, as well as another of Shauntel Hudson Kepner's minor children, were on the cruise. ABC News reported that Kepner's grandparents were also on the cruise.

Kepner was sharing a room with her stepbrother on the trip, the attorney for the boy's father previously said in court. Her father and his mother were married in December 2024.

Shauntel Hudson Kepner said in a prior court appearance related to the divorce and custody case that her son was hospitalized shortly after the cruise ship returned to Miami on Nov. 8, and that he was in counseling following his release. It was not immediately clear why he was hospitalized.

On the day the indictment was made public, Chris Kepner — Anna Kepner's father and T.H.'s stepfather — said "justice needs to be served."

He added "that is where the family stands," when reached by NBC News, noting that he believes T.H. should be in custody.

Kepner was remembered in her obituary as a bubbly, outgoing and reliable high school senior and cheerleader from central Florida. She had dreams of continuing her cheerleading career at the University of Georgia and “loved her siblings deeply,” the obituary said.

"Our daughter's life matters, and we will continue to speak out to honor her, to seek accountability, and to ensure that her case is not forgotten," Chris Kepner said.