More likely she was killed for being in a dangerous situation, in much the same way as Matthew Shepherd was killed. Advising people to avoid such situation does not imply approving of any negative outcomes in they ignore the advice.
you should help the police catch her killers considering the wealth of knowledge you state here
"Killed for being in a dangerous situation"?
Millions of women, myself included, have been in exactly the same situation Natalee was in - even hundreds who were with her - and they were not "killed for being in a dangerous situation."