It's a phenomenon experienced by the families of missing people when a body is never found, experts say: grief without certainty.

Joshua Riibe's return to the U.S. remains unclear as there was no immediate decision about returning his passport, which authorities confiscated last week.

The man who is the last person known to have been with missing University of Pittsburgh student Sudiksha Konanki is on a plane heading back to the US after he obtained a new passport, a source in the prosecutor’s office told CNN Wednesday.