mommy. that s right. what is this one? reporter: your mom was telling us that there are a lot of things you do the way you look that remind her of your father. how does that make you feel? it makes me feel great. makes me feel connected to someone that i basically never knew. but it s really heart warming for me. reporter: diane has never remarried. she still wears her engagement ring. are you happy today? i am. i think despite the horrible tragedy that happened to me and to my mother, i think i ve overcome and persevered and am a really happy person today. reporter: are you, diane? i am happy. reporter: you know what? my guess is your husband and your father would be happy that you re happy. yes. yes, i think so. i m sure he would be happy. what a story, gary. did diane and louis have any specific plans for the 20th
anniversary tomorrow? diane and lewis are very private people and only attended one commemoration in new york city all these years. they like to do things quietly. what they are doing tomorrow is going to a remote part of colorado on a long hike together. just mother and son. wonderful that they have each other. gary, send them our love. that was a really lovely story. reporter: thank you. you can join jake tapper, wolf blitzer, and paula reed as we remember september 11th. live coverage begins tomorrow morning at 8:00 a.m. eastern. coming up a very fond farewell to a friend and legend in our business who has about six minutes to go before he officially retires.
september 11th attacks. in a video released by the white house a short time ago president biden paid tribute to the victims in what he called the central lesson learned that day. we learned that unity is the one thing that must never break. unity is what makes us who we are. america at its best. to me, that s the central lesson of september 11th is that at our most vulnerable, in the push and pull of all that makes us human, and the battle for the soul of america, unity is our greatest strength. the president will visit all three sites of the attacks tomorrow including ground zero where the tribute and light shines tonight to honor the victims. 360s gary tuchman spent september 11th, 2001 and many days and weeks after reporting from ground zero but one story he hasn t told until now, a story that is very personal to him and his good friend. on the morning of september
the evidence seem to support what he told us. i don t need to look him in the eye. sanford police won t comment on whether they put him through such a test when they questioned him but do say they use it as do other police departments. how reliable are they? we contacted an expert who did a study of the devices when used to question suspects about drug use. he says their ability to detect deception is, i m quoting now, no better than flipping a coin. again, we don t know whether the sanford police department subjected zimmerman to such a test nor if they used it as a basis for not charging him. we do know that the lead investigator had suspicions about his story. and now, the mother of a 13-year-old witness to the incident says that same investigator told her so. the lead investigator from the sanford police department stood in my family room and told me this was absolutely not self-defense and they needed to prove it. he told me, and i m paraphrasing this quote, but read