one that has kept him locked up for four months in prison, uncharged. >> reporter: now, an investigationdy without a body, a murder weapon or a clear motive, loses its only suspect. for four months, investigators grilled jegiordano on what they called his suspicious response for gardner's disappearance. almost casually knocking on the doors. and then, there's the $1.5 million travel insurance policy he purchased for gardner the day before they traveled, names himself the beneficiary. giordano has always maintained that gardner has vanished while snorkeling. >> this investigation is going on. for the relatives of robyn in the united states, they are still left without clues, without answers, on what has happened to their loved one. >> reporter: we've learned arub ban authorities would consider extraditing giordano if they find any hard evidence. >> gary's not going to run from anything. he'll come back voluntarily. >> reporter: now, investigators tell us they just begun to sift through the tens of thousands of documents they managed to salvage from gary giordano's blackberry and laptop. t