trayvon martin immediately called for peace and calm in his name. both sides in this case have, in fact, along with public officials from coast to coast. and while there is anger and while there have been outbursts, the talk continues about all the issues central to the case, and that includes race. but after a long and public trial, a jury has pronounced george zimmerman not guilty, and now, the legal conversation and that public conversation still go on. it's where we begin tonight with nbc's ron mott, who covered the trial in sanford, florida, from start to finish. ron, good evening. >> reporter: brian, good evening to you. this verdict landed with a thud 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 -- >> not one more! >> -- 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. >> never again, trayvon! >> 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: the all-women 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, as for trayvon martin's parents, other than a tweet or two since the verdict, they've been largely out of view. brian? >> ron mott starting us off again from 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 presumably, we are talking about something in the category of a hate crime and isn't that notoriously hard to prove? >> that's exactly what the government is looking at, and they are tough cases. the justice department has pledged to take another look at what the fbi has learned about the shooting and the evidence gathered for the trial. but it would be surprising if the federal government brought a criminal case. the hate crime law we're talking about is a relatively new one. it was passed four years ago by congress. it makes it a 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 the 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 con sakz -- convictions under the hate crimes law, there usually has been some other strong evidence showing racial motivation. unless the justice department can come up with something more, a federal case here seems very unlikely. >> we'll keep an eye on it. pete williams, thanks as always. our focus shifts now due to the fact 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 dong rouse dangerous and oppressive heatwave hitting a big part of the country. one of the more sustained we've seen in several years. meteorologist janice huff is with us from a very hot stretch of sixth avenue in midtown manhattan. good evening. >> the temperatures are in the mid-90s in midtown, but it's felt as high a 102 degrees in new york city because of the humidity. these temperatures are not unusual for one or two days. but to have a stretch of what we're expecting is unusual. at least six, maybe seven days of this heat will continue into the early part of this weekend. let's take a look at the temperatures right now across the northeast corridor. it's hot everywhere. a reading of 92 officially in central park, about ten blocks away from me right now. it'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 expectinged to disappear any time soon. from d.c., baltimore, up to boston, there are heat advisories in effect. some relief is expected by the end of this weekend, when temperatures fall 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 all of the sudden. more coming from edward snowden about the nsa and how it operate. 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. glenn greenwald has thousands of documents, as he put it, quote, basically the instruction manual for how the nsa is built. snowden remains in limbo at that airport in moscow. back here, lots of americans 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 gallon of regular now 3.61. that's up 14 cents from one week ago and it goes up from there. we asked nbc's tom costello to 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 that. >> 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 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 that. you 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 are eventually going to go out of business. >> reporter: ice cream man is thinking of parking in a fix 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. tom, 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 the president started. it's now the largest volunteer service organization in the world with four 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 coming to this magnificent house and 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 honored one volunteer on each day of his 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 two million meals to hungry children in 15 overseas countries. still ahead tonight, news of an alarming rise in blood pressure, but this time you can 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. 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 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. >> you bet. 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. autopsy was performed today on cory monteith. the canadian-born co-star of "glee" was found dead on 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 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 richard nixon or never fully comprehend him. and in later 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. it 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 lapse an 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 run 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. finally here tonight, you might have heard already, the big shocker in the book world, a new crime novel, a good one, some folks thought too good for a first-time novelist no one had 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 keyer simmons in london. >> reporter: harry potter made j.k. rowling a famous name around the world. but that famous name was nowhere to be seen when this murder mystery came out in april. "the cuckoo's calling" by robert galbraith, said to be a former military police investigator. some thought he was just too good to be a first-time author. >> i thought this was a fascinating new writer and i think has a lot of future. >> reporter: last week, an anonymous tweet, galbraith is role -- rowling, it said. 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 of them pointed towards j.k. rowling. >> reporter: rowling confessed i hoped to keep the secret a little longer, she said. it's been wonderful to publish without hype or expectation. roweling started as an unknown. she 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 and find it. >> reporter: it has surged to number one on amazon. no, can't find it anywhere. many think this was all a pr if so, it's working. >> certainly let you have a read and i want it back. >> reporter: 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. nbc bay area news starts now. and good evening, everyone. >> new tonight at 6:00. there's a trial in san jose that could have major implications for homeowners throughout california. ten cities and counties are seeking nearly $1 million from paint manufacturers to remove lead paint from millions of homes. especially here in the bay area, a lot of these older homes. >> reporter: that's very true. today during opening statements, prosecutors are argued that five major paint companies knew about the potentially harmful impact lead paint has on children. but continued to sell the product. but the paint companies argued harmful product. in santa clara county, an estimated 400,000 homes were built before 1978. and experts estimate 70% of those houses contain lead paint. they link exposure to lead to learning disabilities. which is why ten california counties and cities are now joining forces to ask that five paint companies pay a total of a billion dollars to remove lead paint from older homes. billion dollars to rcdc in 201d that there is no safe level of lead for children. and we have data showing that in 2010 alone in the ten jurisdictions thre