john lewen and the torrence police department and the cold-case team believed mike lubahn killed hisife carol back in 1981. but they had one big problem. they couldn't prove carol was dead. >> the biggest assumption is going to be how do you know she gent across the country or changed her identity? >> kind of an important question with no answer. and then in january, 2011, jim wallace got the flu. lucky break -- no, really. >> and i was laying in bed, and my wife came in. unfortunately, when you work these cases, all you talk about is we are a dedicated cold-case team. you talk about the case you're working on. i'm sure she was tired of hearing about it. she said, why don't you establish a facebook account for carol. i thought, that could accomplish a great deal. >> of course back in 1981 when carol disappeared, facebook creator mark zuckerberg wasn't even born yet. but 30 years later, detective wallace knew social media and its potential to connect to millions around the globe instantly. it could determine once and for all, he thought, whether carol was alive or dead. >> because all

lewen says the key is suven in the er, or it can lead to a phenomenon called social jet lag. wild time free zone not be to stay up as late as you want, if they're delaying their time by three or more hours, it's kind of like they're living in california on the weekends ask then they have to come back to the east coast for school on monday morning. we know that our bod well for t. >> those dramatic shifts in sleep can lead to swings, changes in a and trouble concentrating. our metabolism isn't functigop immune system is not functioning optimally. >> it's okay to let teenagers sleep in and stay up a little later in the summer, but try to keep it within one hour of their rmal bedtime and normal wake-up times. >> when we come back after a break, summer vacation doesn't mean taking a vacation from your tr special brain drain series continues withs to keep your kids eating right. >> plus,dvice from personal trainer on keeping your whole including fun and easy exercis dale's little girl is heading to college. luckily her dorm is about 10 minutes from a hotel bwyndham. ashley's meeti