Anna Kepner's stepbrother, Timothy Hudson, is asking the court to postpone his murder trial for her death aboard a cruise ship ... TMZ has learned.
According to court docs, obtained by TMZ, Timothy claims his lawyers need more time to get their ducks in a row before the upcoming September trial date.
Timothy's lawyers say they need to do more research, including looking into their client's status as a juvenile and the "different considerations that apply to him and "the unique -- and very unfortunate -- family dynamic that has resulted from the allegations here."
The lawyer says he does "not have the type of access to certain family members that would facilitate their investigation" ... and adds that "more still needs to be done" despite the progress he says he's made on the case.
As TMZ previously reported, prosecutors claim Timothy raped Anna and then killed her in the room they shared on a Carnival Cruise with their family.