in many parts of the country, spawning those demonstrations we have seen since saturday night and tonight, opinions are split about whether justice was done. though race rarely surfaced in george zimmerman's five-week prosecution, suddenly, issues of race are front and center after saturday's acquittal. >> it could happen to anybody's son and we need to stand up to young black males. >> reporter: marches starting over the weekend, many modest in size and mostly peaceful, meander from new york to chicago to los angeles, where notoriously clogged traffic briefly came to a halt on the i-10 freeway. in sanford, they prayed for continued calm. >> we, the jury, find george zimmerman, not guilty. >> reporter: all-woman jury verdict acquitted the 29-year-old zimmerman, who says he killed martin in self-defense after being attacked. >> obviously, we are ecstatic with the results. george zimmerman was never guilty of anything except protecting himself in self-defense. i'm glad that the jury saw it that way and i hope that everyone who thinks, particularly those who doubted george's reasons and doubted his background, now understands the jury knew everything that they knew was enough for them to find him not guilty. >> reporter: prosecutors have faced public criticism about their performance, yet legal experts say it was a tough case to win. >> i think the jury followed the law that they were instructed to follow and given the way that the evidence went in from the prosecution and the defense essentially arguing the same thing that there was a lot of doubt in this case about what happened, that there was no clear version of events given to them, where george zimmerman was not acting in self-defense, this was the only conclusion they could reach. >> reporter: naacp president ben jealous, whose organization's website was flooded with petitioners urging federal intervention, said the zimmerman case marks a call to action. >> we are continuing to do what we have always done, to keep faith in our justice system. but part of keeping the faith in our justice system is being able to access the full extent of our justice system and that's what the people of this country are crying for. >> reporter: sunday, president obama weighed in, writing "i know this case has elicited strong passions. and in the wake of the verdict, i know those passions may be running even higher, but we are a nation of laws and a jury has spoken." this afternoon, attorney general eric holder promised to keep looking into martin's killing. >> the justice department shares your concerns. i share your concerns. >> reporter: tonight, george zimmerman is said to be in hiding, according to attorney mark o'mara. meantime, can as for trayvon martin's parents, other than a tweet or two since the verdict, they have been largely out of public view. brian? >> ron mott starting us off again tonight in sanford, florida. more now on this notion of federal charges potentially against george zimmerman. and in light of the trial just concluded, what those charges could be. our justice correspondent, pete williams, here with us in our d.c. newsroom with more on this and presumably, we are talking about something in the category of a hate crime and isn't that notoriously hard to prove? >> its -- the hate crime lauer talking about is a relatively new one. it passed four years ago by congress and it makes it a federal crime to cause bodily injury to someone because of the victim's actual or perceived race. in other words, the government would have to convince a jury that trayvon martin was shot because of his race, not because of self-defense or some other motive. several former civil rights prosecutors today said it wouldn't be enough, for example, for the justice department to claim that george zimmerman started following trayvon martin because of his race. proving intent, these experts say, is very difficult. when the government has got convictions under the hate crimes law, there has usually been other strong evidence showing racial motivation. unless the justice department can come up with something more, a federal prosecution, brian, seems very unlikely. >> we will keep an eye on it. pete, thanks as always. as always, we shift our fact to the focus that weather is making news tonight. yes, it's summer. and yes, across a lot of this country, it's supposed to be hot right about now, but forecasters are warning about a dangerous and oppressive kind of heat wave hitting a big part of this country, one of the more sustained we have seen in years. meteorologist janice huff is with us from a very hot stretch of sixth avenue in midtown manhattan. janice you good evening. >> temperatures are mid-90s here in midtown but felt as hot as 102 because of humidity. these temperatures are not unusual for one or two days but to have a stretch of what we are expecting is unusual, at least six, maybe seven dives this heat will continue into the early part of the weekend. let's take a look at the temperatures right now across the northeast corridor. it's hot every where. reading of 92 officially in central park, about ten blocks away from me right now. ed's 94 in washington, d.c., and 94 in philadelphia, but it feels like close to 100 degrees because of the humidity. this stretch of heat is up and down the northeast corridor. it's not expected to disappear any time soon. from d.c., baltimore, up to boston there are heat advisories in effect. some relief expected by the end of the weekend with temperatures falling into the 80s but until then it remains dangerously hot across the northeast. brian? >> big strain for utilities as well. janice huff from the heat island of manhattan tonight. janice, thanks, as always. there may be a lot more coming from edward snowden about the nsa and how it operates. the newspaper columnist who first reported on the snowden leak says the fugitive former contractor has sensitive, detailed blueprints of how the security agency operates. glen greenwald says snowden has thousands of documents, basically the instruction manual for how the nsa is built. snowden remains in limbo at that airport in moscow. back here, lots of americans are hitting the road, the peak of summer vacation season. if you're among them, you have seen what we are paying for gas. aaa says the average price for a gallon of regular is now 3.61. that's up 14 cents from one week ago and it goes up from there. we asked nbc's tom cost tell -- costello look at what's driving it this time. tom, good evening. >> reporter: hi, brian. in fact, july and august are typically the peak months for summer driving, as americans pack up for the summer vacation. we are told that is at least one reason why gas prices are moving higher. ♪ summer in los angeles and mike's three ice cream trucks are on the move, but keeping them fueled up costs him $300 a day. nine years ago, it cost half thasummer driving, as americans thathat. >> it affects my bottom line, because at the end of the day, it's what you take home. >> reporter: california has some of the highest gas prices in the lower 48, averaging 4.01 a gallon. in the midwest, it's illinois and chicago where the city averages 4.06 a gallon. the cabbies know -- >> to make a dollar, i have to come up with $75. and nobody has got into my cab, you know? >> i have to have gas in order to go to work. so it affects my life greatly. >> reporter: why the sudden surge? analysts say you can blame a lot of it on the summer driving season. >> this is an old-fashioned case of supply and demand. americans requiring more regular gasoline, refineries producing it, resulting in a decline in crude inventories. >> reporter: there's also concern the unrest in egypt could spread and disrupt the flow of oil through the suez canal. and there have been production hiccups at a few u.s. refineries, helping to push prices even higher. add it all up, an extra 14 cents per gallon in a week, 22 cents in a year, and that 800-mile round trip in the family van from chicago to minneapolis will likely cost about $178 in fuel. looking for the cheapest gas? gasbuddy.com has an app for that. you simply type in your location and the stations with the lowest gas pop up. here in washington, it ranges from 3.59 a gallon to 4.79. some consumer advocates are skeptical with the oil industry's explanation that prices are driven by the markets and not manipulated seasonally by the oil companies themselves. meanwhile, back in los angeles -- >> if the price of gas keeps going up, guys like me will go out of business. >> reporter: the ice cream man is thinking of parking in a fixed location, giving up on chasing oil prices. some analysts we talked to say we may see another ten-cent increase for the gas pump but may be the top for the summer. the big variable continues to be the weather. a hurricane could send prices even higher. brian? >> tom costello, suburban washington for us tonight. thanks. now to the event earlier today that brought us here to washington. the current president and first lady hosted a former president and first lady. george h. w. bush and barbara bush were both saluted for the points of light organization that the president supported. it is now the largest volunteer service organization in the world, with 4 million people putting in 30 million hours of service every year. it was a gracious day, all about the volunteers and a tribute to 41, who, true to form, and in classic modesty, tried to cut off the thunderous ovation he received. he is 89 now. he survived a big health scare last year. and while his legs have quit on him and his voice isn't as strong, it was a familiar-sounding former president who took to the mic briefly. >> like coming home for barbara and me. the rest of you just coming to this magnificent house, to be greeted by this superb hospitality knows no bounds. thank you all very much. >> by the way, his son, neil, says they are calling dad gq instead of 41 these days because of the expressive sock choices he has been making. points of light has honored one volunteer on each day of its existence. today, they handed out award number 5,000 to a retired couple from iowa, floyd hammer and kathy hamilton, who have decided to dedicate their lives to feeding over 2 million meals to hungry children in 15 overseas countries. still ahead tonight, news of an alarming rise in blood pressure, but this time, it's among children in the u.s. tonight, the alarming spike the doctors are seeing and what they are recommending. and later, the critics thought it was just too good a murder mystery for a first-time novelist. turns out, the author had written a few other things. lis turns out, the author had lis turns[ male announcer ]ad pearls. hairbands. and now hot pink toes. seems tough for a tough dog like duke. but when it has anything to do with gwen, he's putty in her hands. for a love this strong, duke's family only feeds him iams. compared to other leading brands, it has 50% more animal protein... ...to help keep his body as strong as a love that can endure anything... even every fashion trend. iams. keep love strong. it's hard to describe, because you have a numbness, but yet you have the pain like thousands of needles sticking in your foot. it was progressively getting worse, and at that point i knew i had to do something. once i started taking the lyrica the pain started subsiding. [ male announcer ] it's known that diabetes damages nerves. lyrica is fda approved to treat diabetic nerve pain. lyrica is not for everyone. and later, the critics as we mentioned, our health news story tonight is important, it is about high blood pressure which, of course, can lead to so many other serious illnesses. a new study out tonight found an alarming increase in children with high blood pressure. our report from our chief medical editor, dr. nancy snyderman. >> you have done amazing. >> reporter: 15-year-old ethan borst is on a mission this summer to get healthy. like a lot of kids, he is struggling with his weight. and more surprisingly, high blood pressure. >> my favorite salty snacks are those little 100-calorie things of popcorn, fritos. that is my weakness. >> reporter: today's study examined over 11,000 children ages 8 to 17 for more than a decade and found an alarming rise of high blood pressure, an increase of 39%. researchers blame obesity for the increase in the number of kids with high blood pressure and they say too much salt is another reason blood pressure levels are so high. >> there's a lot of sodium contained in places you wouldn't expect. it's in yogurt. it's in processed foods. it's in soup. it's even in breads. >> reporter: as for salt, how much is too much? it varies. ages 1 to 3, no more than 1,000 milligrams a day. 4 to 8 years old, 1200 milligrams. ages 9 to 50, 1500 milligrams. these are all markedly less than adding one teaspoon of salt a day. >> small changes can make a big difference. >> reporter: joanna is the medical director at camp shane. >> you guys want to hear some music? >> reporter: where ethan is getting in shape this summer. >> what i have been seeing is lots of young kids with high blood pressure readings. i haven't seen that so frequently in the past. and in fact, i actually sent my machine it in to be checked. >> reporter: stabilizing blood pressure can prevent long-term problems like premature heart attack, stroke and kidney disease, just the type of conditions ethan wants to avoid. he has lost 50 pounds and his blood pressure is now under control. >> the more he continues to lose weight, the more we are gonna try and avoid this high blood pressure from coming back. >> reporter: prolonged elevated blood pressure isn't good for brain growth either, and the concern is if blood pressure remains elevated, that can put pressure on the brain and that might even be a risk factor for dementia later in life, brian. all good reasons to get it controlled. >> dr. nancy snyderman in our home studios in new york. nancy, thanks. also in new york, on wall street today, the markets finished slightly up across the board. the dow, s & p, both hit new all-time highs for the third straight trading session. we are back in a moment after another break with one couple's amazing find along the side of the road. r break with couple's amazing find along the side of the road. before copd... i took my son fishing every year. we had a great spot, not easy to find, but worth it. but with copd making it hard to breathe, i thought those days might be over. so my doctor prescribed symbicort. it helps significantly improve my lung function starting within five minutes. symbicort doesn't replace a rescue inhaler for sudden symptoms. with symbicort, today i'm breathing better. and that means...fish on! symbicort is for copd including chronic bronchitis and emphysema. it should not be taken more than twice a day. symbicort may increase your risk of lung infections, osteoporosis, and some eye problems. tell your doctor if you have a heart condition or high blood pressure before taking it. with copd, i thought i'd miss our family tradition. now symbicort significantly improves my lung function, starting within 5 minutes. and that makes a difference in my breathing. today, we're ready for whatever swims our way. ask your doctor about symbicort. i got my first prescription free. call or click to learn more. [ male announcer ] if you can't afford your medication, astrazeneca may be able to help. [poof!] [clicks mouse] there's doughnuts in the conference room. there's doughnuts in the conference room. automatic discounts the moment you sign up. little things anyone can do. it steals your memories. your independence. ensures support, a breakthrough. and sooner than you'd like. sooner than you'd think. you die from alzheimer's disease. we cure alzheimer's disease. every little click, call or donation adds up to something big. autopsy was performed today on an autopsy was performed today on cory monteith, the canadian-born co-star of "glee" was found saturday in his hotel room in vancouver. he had struggled much of his life with substance abuse and last emerged from rehab in april. the death of this talented young man an enormous shock to the show's global fan base. cory monteith was 31. leonard garment has died. he was richard nixon's white house counsel after john dean left. he advised against not destroying the watergate tapes. he advised nixon to resign and suggested gerry ford as his replacement. he used to say he was born on a kitchen table in a tenement house in brooklyn. garment could never fully explain nixon and never fully comprehend him. and later in years, he represented a full range of clients from wealthy, shady characters to the poorest of the poor as a human rights lawyer. he was a professional jazz musician who played saxophone in the late 1940s for henry jerome's band, where he sat between two other musicians whose names were stan getz and alan greenspan. leonard garment was 89 years old. won't be easy, but the mayor of london wants to buy heathrow airport, build upwards of 100,000 homes on the site and then move heathrow to a different location outside the city of london. heathrow is the size of 35 disney lands. it's the busiest airport in europe by far, and near the top of the list worldwide. because heathrow needs more runways to grow, mayor boris johnson says now is the time to get this right. he says it needs to close due to noise, congestion and pollution. history was made in nascar this weekend. morgan shepherd became the oldest driver ever to start a nascar race. morgan shepherd is 71. all veteran fans know his name and have watched him race for decades. he scraped together a ride this weekend in new hampshire for the top tier nascar race. he dedicated his run to the fans. he lasted 92 out of 300 laps and says if the good lord allows, he is going to try to race in next year's daytona 500. and history was made in major league baseball, at least in terms of fans. this man's name is greg van niel, and at yesterday's cleveland indians home game, he caught four foul balls, that's got to be a record, at least we reckon. somebody give that man a contract. a young couple on their way to a dave matthews' concert pulled over on the side of the road to help a guy out. he had a blown tire on his bike. he was out of luck and stuck and the guy was dave matthews. he was playing that night in hershey, p.a. he was on a bike ride without a cell phone when the flat happened. the nice young woman and her boyfriend enjoyed backstage passes after saving the day and the lead singer. when we come back, the plot twist very few people saw coming. . when we come back, the plot twist very few people saw coming. my mantra? trust your instincts to make the call. to treat my low testosterone, my doctor and i went with axiron, the only underarm low t treatment. axiron can restore t levels to normal in about 2 weeks in most men. axiron is not for use in women or anyone younger than 18 or men with prostate or breast cancer. women, especially those who are or who may become pregnant and children should avoid contact where axiron is applied as unexpected signs of puberty in children or changes in body hair or increased acne in women may occur. report these symptoms to your doctor. tell your doctor about all medical conditions and medications. serious side effects could include increased risk of prostate cancer; worsening prostate symptoms; decreased sperm count; ankle, feet or body swelling; enlarged or painful breasts; problems breathing while sleeping; and blood clots in the legs. common side effects include skin redness or irritation where applied, increased red blood cell count, headache, diarrhea, vomiting, and increase in psa. ask your doctor about the only underarm low t treatment, axiron. 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[ male announcer ] that's handy. ♪ finally here tonight, you mi finally here tonight, you might have heard already the big shocker in the book world, a crime novel, a good one, some thought too good for a first-time novelist no one ever heard of. then we learned the truth, and put it this way, good luck finding a copy of this book right about now. the story tonight from nbc's keir simmons in london. >> reporter: harry potter made jk rowling a household name around the world. but that was nowhere to be seen when this came out in april. "the cuckoo's calling" by robert galbraith, thought to be a former military investigator, some thought he was just too good to be a first-time author. >> i wrote this great review about what i thought was a great new writer and he has got a lot of future. >> reporter: last week, an anonymous tweet, galbraith is rowling. the paper launched an investigation. >> there's something we need to find. >> reporter: hired a language expert to compare the writing and found literary gold. >> in this case, what happened when i ran the statistics, every one point jk rowling. >> reporter: rowling confessed. i hoped to keep the secret a little longer, it has been wonderful to publish without hype or expectation. she started as an unknown, showed this documentary crew this tiny apartment in scotland where it all began. fame became a burden at times, but she vowed to keep writing, even after harry potter. >> i will always write. i can't imagine stopping writing. >> reporter: harry potter sales are close to half a billion. "the cuckoo's calling" had sold just 1500 copies, but try finding one today. no? no galbraith at all? >> yeah, we're trying to run all over around find it. >> reporter: it has surged to number one on amazon. no, can't find it anywhere. many think this was all a pr stunt. if so, it's working. >> certainly let you have a read, but i want it back. >> reporter: the publisher plans to print more, to solve another mystery, how to find another copy. keir simmons, nbc news, london. and that is our broadcast on a monday night. thank you for being here with us. i'm brian williams. we hope to see you back in new york tomorrow evening. good night. [ male announcer ] you know what's so awesome about the internet? it gets more and more entertaining every day. and once you've got verizon fios, that's when you get it -- how 100% fiber optics takes your entertainment to ridiculous levels. i was streaming videos, movies, music. once i realized how fast it was, that's when i got it. 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