allan mongold: yeah, off we go to chris.tions, when's the last time you saw robin, what's y'all's relationship, who doesn't like her, the same questions. i was here, mom's in the house, i live with my mom, talk to her. he had an alibi. he had an alibi. so chris is off the list. nobody gets off the list that early, but yeah, he's at the bottom. josh mankiewicz (voiceover): jared soon moved to the bottom, too, but jd was about to move up the investigators list because his story was about to change. coming up, an ex-husband caught in a lie, coming up, an ex-husband caught in a lie, when "dateline" continues. i'm getting vaccinated... ...with pfizer's pneumococcal pneumonia vaccine. so am i. because i'm at risk for pneumococcal pneumonia. i'm getting prevnar 20 because pneumococcal pneumonia could put me in the hospital and my risk is 6 times greater because i'm over 50. the cdc just expanded its recommendation for those 50 or older to get vaccinated. you're also at risk if you're 19 or older with certain chronic conditions. pre