Step-grandmother of suspect in Anna Kepner case calls for charges against Kepner's father, stepmother

The step-grandmother of Timothy Hudson, the 16-year-old stepbrother of Anna Kepner who has been charged in her death and sexual assault, is calling for charges against Kepner's father and stepmother over alleged neglect during their cruise vacation.

Kepner, an 18-year-old high school cheerleader, was on a Carnival cruise ship with her family, including her father and stepmother Chris and Shauntel Kepner, when she was killed.

"The lack of parental supervision on a floating city," said Sonya Ziske, who says she helped raise Hudson. "Putting three teenagers, two boys and a girl in a room together that were not raised together, It's just a recipe for disaster."

This is the first time Ziske, who is also Shauntel Kepner's stepmother, has spoken to the media about the incident. According to Ziske, when she and her husband, who is Shauntel Kepner's biological father, tried to reach out to her about the incident after reading reports about it online, she wouldn't explain what happened.   

"Whatever you do, just don't talk to the media," is all Shauntel Kepner told them, according to Ziske.

Hudson has told his family he has no recollection of the night Kepner died. Ziske believes alcohol was involved and that he may have blacked out.

"He truly does not remember," Ziske said. "Timothy has said that they were drinking. I believe 100% those kids were drinking on the ship."

Shauntel and Chris Kepner have previously denied the children were drinking through their attorney during a family court hearing related to a custody battle.

"The issue that counsel raised about drinking, there are videotapes on the ship that confirmed that there was absolutely no drinking," said Millicent Athanason, an attorney for Shauntel Kepner during a November custody hearing.

"Here, the question is, did the parents do something or fail to do something that enabled their child to commit this horrific crime?" said Dave Aronberg, former Palm Beach State Prosecutor, about how investigations on parental neglect typically take place. He is not involved in this case.

"It's a very fact-based inquiry, and I don't know if there are enough facts to sustain that charge," he told CBS News.

Despite being charged as an adult and facing first degree murder and sexual assault charges, Hudson is not being detained because he is a minor.

Being charged in a federal court has vast protections for minors, including that they be held near their family or, whenever possible, a foster home or community-based facility.

"I'm not saying he did, or he did not. I'm saying it's not his character," said Ziske. "Everybody's out there saying how he's walking free. He is not free. His life is over, whether he is innocent or guilty."

Hudson is currently in the custody of his maternal uncle, but has spent time with Ziske and other family members, including his young cousins who live with him in a home in Florida's Tampa area.

Ziske believes Chris and Shauntel Kepner are unfit to have custody of the remaining children, given what allegedly transpired on the cruise ship.

"She kept them isolated from everybody over here. From their dad, from their grandparents. From all of us," Ziske said. "So, I don't know the past two years. Like, if he was angry, or his mental state, I don't know any of that."

New court documents obtained by CBS News reveal authorities recovered Anna Kepner's cell phone from the ship's lost and found. The phone had been recovered from a trash can where Hudson allegedly was seen on surveillance video apparently disposing of the device.

According to the court documents, Hudson and Anna Kepner were alone in the cabin they shared from about 7:51 p.m. to 11:21 p.m. the night of the incident.

Prosecutors allege Anna Kepner's Apple Watch, which tracked her heart rate, stopped working during this time, which they believe is when the crime allegedly occurred.

CBS News reached out to Chris and Shauntel Kepner's attorney, who did not respond to our inquiry.