here. >> reporter: arguing their case today, conservative ted olson who joined with david boise. once foes over the 2000 election in florida. >> this is not a democratic issue or republican issue or conservative or liberal. this is an issue of american constitutional rights. >> reporter: defenders of prop 8 say, because only opposite sex couples can produce children, it makes sense to limit marriage to them. >> it's impossible to know with any certainty the changes that would be worked on society by redefining the institution of marriage. >> suppose a state said, because we think that the focus of marriage really should be on procreation, we are not going to give marriage licenses any more to any couple where both people are over the age of 55. would that be constitutional? >> reporter: the court's conservatives were equally

skeptical that gay couples have a right to marry. >> i'm curious, when did it become unconstitutional to exclude homosexual couples from marriage? 1791? 1868, when the 14th amendment was adopted? >> reporter: they said though gay couples in california have all the rights of married couples, letting them be called married would be a big change. >> if you tell a child that someone has to be their friend, i suppose you can force the person to say, this is my friend, but it changes the definition of what it means to be a friend. and that's what it seems to me the supporters of proposition 8 are saying here. >> you want us to step in and render a decision based on the assessment of the effects of this institution that is is newer than cell phones or the internet? >> reporter: just as kennedy, the pivotal vote seemed to throw up his hands. >> you're really asking, particularly because of the sociological evidence you cite for us to go into unchartered waters.

i just wonder if the case was properly granted. >> so that could be what the court does, say it should not have taken the case in the first place because there's no clear answer. that would leave the lower court ruling in tact that struck prop 8 down. same sex marriage could resume in california, but there would be no nationwide precedent. brian? >> it will be interesting to see how tomorrow's case is informed by tomorrow's discussion. pete williams will be there tomorrow's case as well. pete, thanks. as we mentioned here tonight, public opinion toward same sex marriage has been changing so fast. almost moving 1 percentage point a year lately in a lot of polls. most americans now say they have a gay friend or family member. some of the change is generational and then there's our media culture. that side of the story tonight from nbc's kristen dahlgren in los angeles. >> reporter: when ellen degeneres came out in 1997. >> gay woman in aisle 5. >> reporter: it was front page news.

"will & grace" soon brought gay men into living rooms week after week. >> you still want to marry me? >> over and over and over. >> reporter: fast forward to a few years to what is considered a modern family, and one of the most popular shows on tv. >> our game nights on saturday, they're epic. >> reporter: over the years, television has changed the conversation about american sexuality. and what happens in hollywood doesn't stay there. as shows created an era of acceptance, more and more real men and women came out of the closet. meaning more and more americans now personally know someone who's gay. >> the combination of knowing gay people personally and knowing gay people through the media are convincing people that gay people are people, they have lives, they have loves, they have families. >> reporter: in a recent nbc poll, for the first time, a majority, 51% of americans are now in favor of same sex marriage. up from just 30% in 2004.

last week, republican senator rob portman publicly supported same sex marriage after his son came out. of course, nearly half of americans still oppose it. >> maybe that's the way i was brought up, a marriage is an institution that's between a man and a woman. >> reporter: leaving opponents now watching just as closely as christine hershey and suzie van horn. partners for 33 years and parents to chris. like many, now waiting to see what happens in the supreme court and the court of public opinion. kristen dahlgren, nbc news los angeles. a stunning legal decision in rome today is reverberating in this country tonight. italy's highest court has decided to retry american college student amanda knox for the murder of her roommate in italy more than five years ago. even though knox had already been acquitted of the crime. michelle kosinski has our report tonight from rome. >> reporter: the italian court's decision came as a surprise, to

retry amanda knox for murder. >> she's shocked, very sad. she thought this was the end of a nightmare. but she is also very strong, in the sense that she's willing to fight again. >> reporter: in a statement, knox called the ruling painful. the prosecution's theorys un founded, unfair. my family and i will face this continuing legal battle confident in the truth. knox, now 25, lives back home in seattle. a student at the university of washington, with a book coming out. living in italy in 2007 she and then boyfriend, raffaele sollecito were convicted of murdering her roommate meredith kerchner. knox spent nearly four years in jail, until the conviction was overturned on appeal. prosecutors appealed that acquittal, saying the court has essentially brushed aside all the evidence, dna, witness statements. the judges haven't yet spelled out why exactly they sided with prosecutors. the case will go to an appeals

court for retrial, which could take years. with a new verdict not expected until 2016. this morning on "today" knox's lawyer was exasperated. >> there was no evidence before, and there is no evidence now. >> reporter: you know people are criticizing the italian legal system saying, is there something wrong with it? >> no, this is the way the italian legal system works. the supreme court is called to judge on matters of law, and this is exactly what it's done. >> reporter: knox will likely be tried in absentia. if convicted italy could ask the u.s. to extradite her, but it's not likely the u.s. would. they've refused in other cases. meredith kercher's family says they welcome a retrial to find out the truth. still fiercely debated six years later. michelle kosinski, nbc news, rome. new threats of nuclear attacks are rumbling out of north korea again today aimed directly at the u.s. and the

pentagon is responding. while u.s. intelligence and military officials are wondering just what this new and untested 28-year-old leader might be up to. our pentagon correspondent jim miklaszewski is on duty from there tonight, good evening. >> reporter: good evening, brian. today's warnings from north korea are the latest in a series of provocative threats, which have forced the u.s. and south korea to plan for possible military retaliation. the north koreans claim they put their long range missiles on high alert, aimed at american targets in guam, hawaii and the u.s. mainland. u.s. officials see no sign of an imminent attack, but they're taking no chances. the u.s. and south korea signed a military agreement just last week that in the event of a north korean attack, the two allies could combine forces for a counterattack. now, officials here don't believe that north korean president kim jong-un wants a full scale war.

some fear his unpredictability makes him extremely dangerous, brian. >> jim miklaszewski watching it all from the pentagon tonight. jim, thanks. president obama today named long-time secret service agent julia pierson as the agency's new director. it will mark the first time a woman has ever held the top job. pierson moves up from the chief of staff role at the agency. known most widely for protecting presidents and their families. she takes over now from long time boss, secret service veteran mark sullivan. who dealt with the wake of the prostitution scandal that wounded the agency's reputation. north dakota's governor today signed into law the tough est restrictions on abortion in this country. banning abortion once a fetal heartbeat can be detected which is usually around six weeks into pregnancy. most experts say the new law violates the nationwide standard under roe versus wade. the supreme court decision. and even supporters of the new measure expected to be overturned. anti-abortion leaders say

they're trying to test the boundaries of roe versus wade at the state level. turning now to the economy and the real estate market at home. home prices are rising at the fastest pace since '06 when we were at the peak of the housing bubble. this is a big change. it may sound like good news if you're thinking of selling. but buyers, especially first timers, are increasingly finding themselves in a squeeze. diana olick from cnbc is with us tonight from washington. diana, good evening. >> reporter: good evening, brian, for the past seven years, homeownership in america, has been falling steadily. as housing finds new life again, the dream of ownership is edging back and potential home buyers are waking up. >> this is the place. >> reporter: newlyweds brian and alley earl are ready to buy their first home in alexandria, virginia. >> this is pretty spacious too. >> reporter: with the housing market now in recovery, renting just doesn't add up.

>> we've probably gone up, 20%, 25% in rent. at this point the price we're paying for rent we could be doing for a mortgage. >> reporter: near record low mortgage rates, job growth, and a drop in distressed properties has more americans encouraged about housing. a new cnbc survey finds 79% now say owning a home is an essential part of the american dream. a three-year high. those who say it's better to own than rent also grew to 69%. this new-found excitement is hindered by a severe shortage of homes for sale nationwide, down 19% from a year ago. go local and the drops are more dramatic, in boston, houston, denver and seattle. in the atlanta area, where home listings are down almost 40%. >> all of these are a four bedroom, five bedroom homes. >> reporter: leah wilson jacobs, a married nurse and mother has put in offers for homes in the $100,000 range. >> i usually bid $2,500 to

$3,000 over asking price. and each time we've been outbid. >> reporter: in formerly hard hit las vegas, big money investors are buying everything in site. >> there's at least 10,000 individual primary homeowners that are put on the sidelines, because the hedge funds are coming in and absorbing the assets. >> reporter: investors largely pay with cash and it shows. all cash sales rose to 1/3 of the market in february. >> will this be enough space for you? >> just enough. >> reporter: as new listings are added for spring, regular buyers like the earls who are preapproved for a mortgage are losing out. in alexandria, there are just 255 homes for sale, a 31% drop from a year ago. >> we have to be on top of the game, and be able to drop everything and check out a house or it will be gone. >> reporter: investors have been pushing home prices higher faster than expected. but the higher prices get, the more investors may get out, because they won't be able to find such great bargains any more. that in turn will let regular buyers back, in even if they do have to pay a little more to own. brian?

>> diana olick in front of an available property in d.c. tonight. diana, thanks. when we continue, after a devastating string of tornados. reuniting people and their property and what it's teaching us about the storms at large. later, the teenager who spent way too much time on his computer, and how it's made him a millionaire many times over.

the start of spring means after a violent year last year, here we go again. the start of tornado season. and in the aftermath of such a large outbreak in the southeast, one woman responded by trying to connect people with some of the property they lost, when it became airborne. and it turns out what started as an act of kindness genuinely is having another effect. it's teaching forecasters more about how tornados behave. our report tonight from nbc's kerry sanders. >> reporter: when a tornado touches down. >> i can't believe it hit that. >> reporter: nothing, not even an 18 wheeler is safe.

>> this is something i've never seen before. >> reporter: meteorologists can predict with some accuracy where wind in excess of 200 miles an hour will form twisters and strike. >> you need to be taking shelter right away. >> reporter: they're only just beginning to understand what happens to debris sucked into the tornado's vortex. >> the house is coming apart. >> reporter: the science has come from the most unlikely of places, facebook. >> this is one of the things that was found. >> reporter: patty created a lost and found page after she picked up an ultrasound image in alabama front yard. >> it broke my heart that it was at my house and i didn't know where it belonged. >> reporter: 120 twisters ripped through the southern u.s. in the spring of 2011. people posted on facebook at least 2,000 keepsakes that were eventually reunited with their owners. >> that's where the debris went. >> reporter: scientists realized for the first time they had hard data of where items started and ended up.

>> "the wizard of oz" with dorothy going up and the house spinning around and around may not have been quite as crazy as we think, except it's not entire houses that spin around, it's the debris from houses. >> reporter: the facebook page connected a cheerleading jacket found in elkmont, alabama, with its owner 66 miles away. and this five foot high memorial from the football field in smithfield, mississippi found 69 miles away in russellville, alabama. and this photo landing more than 220 miles away in east tennessee. >> if a tornado is coming but it misses you, you might still be in danger of having debris fall on your property or on your house. >> reporter: tornados with facebook converging to better understand mother nature. kerry sanders, nbc news, miami. when we come back tonight, the news a lot of people never thought possible. the upcoming royal visit to the jersey shore.

pedro quezada came to new jersey 26 years ago as an

immigrant. he went to work at his convenience store at 5:00 a.m. every day. tonight he is a very wealthy man. he accepted his winnings today in that $338 million powerball jackpot at a news conference, he told reporters, he felt pure joy upon learning of his good fortune. he says, he'll use the money to take care of his family, including five children at home. as you may know, it is the best place to be in the summer, sooner or later all the cool kids go there. and sure enough, prince harry is coming to the jersey shore. as part of his next u.s. trip in may. he will be touring some of the devastation from hurricane sandy. he's going to check in on the relief effort. new jersey governor chris christie says he's thrilled the prince wants to focus attention on his state. and promises to keep an eye on him while he's there. dionne warwick has filed for bankruptcy. the grammy award winner owes $10 million. mostly in back taxes. her publicist blames it on years

of negligent financial mismanagement. the five-time grammy winner is listing personal assets of only $25,000. what's the chance the two men, one of them president of the united states, the other secretary of state would attempt headers of a soccer ball on the same day half a world apart? well, it happened today. the president was awarding the major league soccer champions, the l.a. galaxy -- well done there -- and secretary of state john kerry was in afghanistan, with the afghanistan women's soccer team at the u.s. embassy in kabul, perhaps a less spectacular result. when we come back here tonight, if you know someone who spends way too much time on the computer, maybe this young role model will change your mind.

a 17-year-old high school kid in the u.k. with a bright idea and some serious computer skills is the world's newest internet millionaire. even before he's finished in high school, he's got a big time job at a big name tech company, and we get his story tonight from nbc's chris jansing. >> reporter: with his artfully messy hair, mischievous smile, and colorful shoes nick looks

like a normal 17-year-old. but then he starts to talk. he is describing his invention, called summly, a smart phone app that takes a news story and summarizes it. and he just sold it for $30 million to yahoo!. >> it's pretty overwhelming. >> reporter: no kidding, his story, echoing that of mark zuckerberg, except nick is a lot younger. >> i've been doing apps on and off since i was 12. >> reporter: he started making money right then. it was summly that caught the eye of a hong kong billionaire when nick was all of 15. >> the question was, when are we going to meet you? i was like, before or after school? >> reporter: other unexpected investors followed, yoko ono, ashton kutcher and rupert murdoch. nick is believed to be the youngest person ever to attract

venture capital. a title, entrepreneur brian wong held a few years ago. >> of course it makes me feel old. once you pass legal drinking age, it's like, there's no more novelty factor. >> reporter: suddenly nick is a role model for teen tech whizzes with an idea and a dream. he taught himself basic programming and took inspiration from the movie about zuckerberg, "the social network." >> a million dollars isn't cool. you know what's cool? a billion dollars. >> reporter: nick says he didn't do it for the money. besides, he still has another year and a half of high school. the job at yahoo!. then he hopes to study philosophy at oxford. what then? >> i don't know. i'm still leaving options open. it's okay, he still has time. chris jansing, nbc news, new york. >> remember just having to worry about who to take to the senior prom? by the way, you can see nick live tomorrow morning on "today." as for us, that is our broadcast on a tuesday night. thank you for being here with us. i'm brian . pe to

see you right back here tomo right now at 6:00, a bizarre mystery leaves a girl in the hospital. the errant arrow that has police baffled. the college students working hard to prepare for their finals as their administrators prepare to bring back many of the classes that have been cut. coming up, a long-term study on the impacts of budget cuts on our community colleges. and then an emotional toil. local workers clocking out for good and ushering in a new technological era. good tuesday evening, i'm janelle wang. >> and i'm jessica aguirre. we begin with history in the making. several cities across the bay area raised rainbow flags as the supreme court for the first time ever heard arguments in the same-sex marriage debate. >> outside the nation's highest court in washington, d.c.,

thousands of supporters and opponents of same-sex marriage clashed in dueling demonstrations. inside the justices heard just over an hour of arguments for and against california's voter-approved prop 8 which bans same-sex marriage. whatever their decision, which is expected this june, it will be a landmark ruling. we have live team coverage tonight. cheryl hurd spoke with gavin newsom and is live at a pro gay marriage vigil. >> but we begin with marianne favro who's here with a closer look at what was said and what hints the justices may have given the crowd. >> reporter: the u.s. supreme court justices spent quite a bit of time today questioning whether this is a case they should even be hearing, and legal experts say there are early indications they might want americans to decide on same-sex marriage instead of the court doing it. for 80 minutes, justices listened to oral arguments. some legal experts say it appears some had concerns about the possibility of a sweeping decision affecting 50 states.

chief justice john roberts. >> you don't have to include everybody just because some other aspects of it can be applied to them. >> justice anthony kennedy questioned whether anyone would be harmed by allowing same-sex couples to marry. >> are you conceding the point that there is no harm on denigration to traditional opposite-sex marriage couples? >> reporter: supporters of the ban argue that it protects the traditional marriage and its intent of having kids. >> and it will refocus, refocus the purpose of marriage and the definition of marriage away from the raising of children. >> reporter: justice alana kagan pointed out california doesn't ban older people getting married. >> if both the woman and the man are over the age of 55, there are not a lot of women coming out of that marriage. >> reporter: justice scalia had questions about the children of gay couples. >> whether that is