. >> reporter: major general donna martin conducted the criminal investigation division, which investigated i think there is an investigation misperception out there, that because we see some of these shows on tv, that evidence just turns up. it doesn't happen like that and we are life. >> how important was this investigation to you? she says behind the scenes, the investigation was more intense than anyone realized. she will take us inside it next. coming up -- >> they are searching their company areas, the installation, they are looking everywhere for vanessa. >> reporter: on base, a frustrating hunt for clues. any blood evidence? >> there are no signs of blood. >> no signs of struggle? >> no. >> it's like she vanished into thin air. >> almost. when "dateline" continues. "dateline" continues. u never knew what a dog could do for you. and with resolve, you never worry about the mess. love the love, resolve the mess. we're carvana, the company who invented car vending machines and buying a car 100% online. now we've created a brand-new way for you to sell your car. whether it's a year old o

ah, well martin got his fels wife donna claims. he is currently on hunger strike. and in solitary confinement, she says she's worried about him and has not had any contact with him for a back to week earlier, donna spoke to my colleague colleen brian. the last time anyone heard from him is september 23rd. and when he is put in, in solitary, it usually are almost always comes with a hunger strike. and the conditions are still deplorable from a water in it drinking water. they corrode metal, q hot steam pipes. it's very dangerous that places so scary. i spoke to a lawyer the other week that told me that it's the worst president in the united states. and the shield is different than even the shit they use for the rest of the facility. it's. it's really scary to say that martin's been stripped of his phone and i was shortly after your last conversation. why was that? it's just a temporary punishment. will you be warned that communicating with us here at r t could violate prison rules. we believe that it's retaliatory and for speaking out against the prison, rape elimin