on our broadcast tonight, october surprise, chris christie endorses mitt romney, and we have the exclusive interview with both men tonight. the plot, murder for hire. huge sums of money and links to the iranian government. the u.s. says it stopped a huge international conspiracy. but does the story all add up? risky business. more surprising news about prostaoste ccer. this time it's another popular vitamin supplement that may be doing more harm than good. and the interrogation of michael jackson's doctor. today jurors heard conrad murray's emotional description of what he told jackson's children on the day he died. "nightly news" begins now.

captions paid for by nbc-universal television good evening. he remains one of the biggest names in republican politics. we just watched new jersey governor chris christie carry out a personal yet public deliberation over running for president himself. he said no. but today he made a rare and early endorsement for mitt romney for the gop nomination. some republicans, as you know, have shown buyers remorse at the thought of a romney nomination. there's still a big gop market out there for a more conservative candidate. and the ranks are still shifting tonight, but as you're about to see in our exclusive interview with christie and romney together, today they were all about one republican party going-forward. we begin our coverage tonight with our political director chief white house correspondent, chuck todd in d.c. chuck, good evening. >> good evening, brian. we're at a strange moment in this republican race. just as polls are showing the race is wide open, there's a

growing movement among insiders to rally around the fragile front-runner, mitt romney, and that was on display today with chris christie trying to cement romney's chances. a clearly enthusiastic mitt romney today. >> it's an honor to be joined today by governor chris christie. >> reporter: and christie was quickly on romney's message. >> you look at mitt romney's experience, his experience in the private sector, running businesses, turning them around, going in there, telling the people the truth about what needs to be done. >> reporter: it was a case of life imitating art. here's "saturday night live's" spoof just four days ago. >> he's a nice man in a clean suit that wants to be president. >> reporter: today the real romney and christie took questions. first up, romney's religion, and the weekend dustup where rick perry called mormonism a cult. >> i think any campaign that associates itself with that type of conduct is beneath the office of the president of the united

states, in my view. >> reporter: romney directly implicated perry himself. >> i don't believe that that kind of thinking about religion has a place in this country. i would call on governor perry to repudiate the sentiment and remarks made by that pastor. >> reporter: christie summed up his reasons for endorsing romney with a jab at candidate obama. >> people run for president of the united states because they think in their minds, i think i can win, i hope i'm ready. mitt romney says, i hope i can win, i know i'm ready. >> reporter: the endorsement comes at a time when perry was hoping to regain traction against romney, starting with tonight's debate in new hampshire. but he's got a new hurdle, ex-godfather's pizza ceo, herman cain. new nbc polls in iowa and new hampshire show cain surging. in iowa, romney and cain are neck and neck with perry in fourth. in new hampshire romney's lead is bigger, but again, it's cain in second and perry in fourth. don't forget iowa and new hampshire are swing states. president obama does not fair well in either state.

bad job approval numbers, loses to romney by 9 points in our nbc news poll in new hampshire, brian. >> chuck todd in our d.c. newsroom starting us off. chuck, thanks. as we mentioned, these two men only granted one sitdown interview today. it was with nbc's jamie gangel. she's with us tonight from lebanon, new hampshire. jamie, good evening. >> reporter: good evening, brian. this is a big endorsement for mitt romney. it sends the message that he's the choice of a popular republican governor that many in the party wanted so run. and romney left open the possibility that if nominated, he would consider chris christie for vice president. why are you endorsing him? >> he's the best person for the job. it's simply on the merits, and the fact is, that we need to make sure that barack obama's a one-term president for america's future. and i've looked at all the republican candidates, i've met with many of them. and there's no question in my mind that governor romney is the person who gives us the best chance of winning back the white

house in 2012. and i want to do everything i can to help him. >> did he promise you anything? >> absolutely nothing. >> vice president christie? >> no. >> no? >> no, he didn't promise me anything. >> would he be on your short list? >> of course, he would be on anyone's short list. he may take himself off the list and say, no way, he would have no interest. but the truth is, governor christie is one of the leading figures in the republican party. and is someone who has taken on extreme interests inside his state, has battled them down and balanced the budget in new jersey without raising taxes and creating the kind of environment that will ultimately create more and more jobs. it's what america needs. >> reporter: and, you know, brian with his plain speaking, no nonsense style, chris christie will be a tough surrogate out on the campaign trail. brian. >> all right, jamie gangel in lebanon, new hampshire tonight. jamie, thanks. you can see more of this interview exclusively tomorrow morning on "today." now, to the midafternoon news conference that got

everybody's attention. the u.s. attorney general came to the podium and said the united states had indicted two iranians and foiled an alleged terrorist plot that involved mexican drug lords, murder for hire, and a lot of money to kill the saudi ambassador. as he laid out the details, it all sounded so outlandish. a lot of people wondered if it was all for real. with us from our washington bureau tonight, our chief foreign affairs correspondent andrea mitchell. andrea, good evening. >> good evening, brian. we've been running the trap. the attorney general and fbi director laid out a plot that on its face sounds bizarre. but u.s. officials insist it was a real plot to assassinate the saudi ambassador and bomb his offices here in washington. >> though it reads like a hollywood script, the impact would have been very real and many lives would have been lost. >> reporter: an alleged $1.5 million plot to assassinate saudi arabia's ambassador, a

veteran diplomat and king abdullah's right hand man by blowing him up in a washington restaurant and bombing the saudi embassy in washington. u.s. officials tell nbc news a secondary plot was to target israel's embassy in washington. the accused, an iranian-born u.s.-citizen, manssor arbabsiar, was arraigned in manhattan this afternoon. a co-conspirator named in the indictment remains at large. but the administration says iran's government was behind it all. >> the plan alleges this conspiracy was conceived, sponsored and was directed from iran. >> arbabsiar was arrested 12 days ago and has been cooperating ever since. when pressed, even u.s. officials acknowledge it sounds leak a cheap thriller. according to the complaint, since last spring, arbabsiar met in mexico with a man he thought was a member of a drug cartel, trying to hire an assassin to kill the saudi diplomat. but from the start, the mexican was an agent for the u.s. government. the iranian even got $100,000 supposedly wired from iran to

the u.s. as a downpayment to kill the saudi ambassador at a washington restaurant. when the agent warned there could be also be senators dining there, others could die. arbabsiar supposedly said, no problem or no big deal. >> there are a lot of details about this that sound a little too salacious to be true. it suggests a willingness to act aggressively, even recklessly on the part of the iranian regime that, quite frankly, we haven't seen from the iranians since the 1980s. >> reporter: tonight iran's television dismissed the plot as a u.s. fabrication. the u.s. treasury, though, has sanctioned five iranians, including the man who has led a powerful force for more than a decade. >> this kind of action which violates international norms must be ended. >> reporter: today president obama visited the team that worked on foiling the alleged plot in the situation room to thank them for their work. and he also called the saudi ambassador to express solidarity. u.s. officials say top iranian officials either knew about the

plot or they have a military force running amok. either way, they have to explain this to the world. brian? >> andrea, i know it's guesswork, is this the kind of thing where we're likely to see saudi retaliation? >> i don't think you'll see direct retaliation. i think that they're going to take their time. but this certainly sets the stage for what could be saudi retaliation, israeli retaliation. this has a lot of people on edge tonight. >> all right. andrea mitchell with the story out of washington tonight for us. andrea, thanks. a man accused of trying to blow up a passenger plane headed to the u.s. on christmas day two years ago now, he went on trial today in detroit, in federal court there. prosecutors told the jury that the so-called underwear bomber, who's representing himself in this case, by the way, went to an airplane bathroom late in the flight, performed a religious purification ritual, washing and perfuming himself before returning to his seat trying to set off the bomb that was sewn into his underwear. you'll recall this was the attempted attack that led to the full body scans and intrusive

patdowns at american airports. remember that big jobs bill president obama proposed? it went down in defeat in the senate tonight. they were unable to get the 60 votes needed to keep it moving. they will now try to break up the $447 billion measure into smaller parts and pass those individually. those occupation protests continued today in several u.s. cities, including a group of community organizations that staged what they called a millionaires march here in new york city. demonstrating in front of apartment buildings that are home to some prominent new yorkers, mostly in media and finance. in washington, meantime, protesters from the same occupy wall street movement were arrested when they occupied the hart senate office building amid chants of "we will not be ignored." in los angeles, it's been another emotional day at the trial of michael jackson's physician, as jurors heard more

of dr. conrad murray's police interrogation, conducted just days after jackson died. and they heard from the man who conducted the autopsy in this high profile case. nbc's jeff rossen is covering the trial for us from downtown l.a. >> reporter: dr. conrad murray sat silent today as his words echoed through the courtroom. >> so we brought them into the room. >> reporter: after jackson's death, murray described to police the heartbreaking scene inside the hospital as jackson's kids, prince, paris and blanket learned their dad had died. >> the children cried and cried and cried. paris said she didn't want to be an orphan. and she asked me, dr. murray, she said, you save a lot of patients. you save people with heart attacks. you couldn't save my dad. now i'll wake up in the morning and i won't be able to see my daddy. >> murray said jackson's mother

katherine was in shock too. >> well, how is he? he's not dead, is he? and the doctor said yes. and she broke down. >> reporter: prosecutors say murray gave jackson a lethal dose of propofol, but they also found other drugs in the singer's mansion. >> i was not aware of other medications that he was taking, but i heard that he was seeing a dr. klein three times a week in beverly hills. and he never disclosed that to me. >> reporter: dr. klein, a dermatologist, has not been accused of any wrongdoing. >> we found a small portion of marijuana in his room. did you know him to be a smoker? >> no. but he used excessive cologne. >> reporter: later in the day, l.a.'s deputy medical examiner took the stand, telling the jury this was a homicide. and the doctor murray story that michael jackson injected himself with propofol just isn't reasonable.

prosecutors could rest their case this week, and then murray's defense team takes center stage. jeff rossen, nbc news, los angeles. and still ahead as "nightly news" continues on a tuesday night, as if all the confusion over the tests for prostate cancer isn't enough, now there's news that a popular vitamin that tons of people take may not be doing its job at all. and later, "making a difference" for the kids of moms and dads serving far from home in uniform.

tonight's health news story, as we said, is another example in a string of them, of something we have been told is good for us, but turns out not to be, at least according to the latest study. last night we began this broadcast with the news that some of those ubiquitous vitamin supplements may be harmful for older women. less than a week ago we were told the psa, the benchmark prostate cancer test we've been told about for years, may not save lives afterall. tonight there is more about prostate cancer, and the headline here is, vitamin e may have exactly the opposite effect than most people taking it may think. our report tonight from our chief science correspondent robert bazell. >> reporter: bill ross started taking vitamin e regularly more than 20 years ago on his doctor's advice because he has a strong family history. >> my father is a prostate cancer survivor.

he's been battling prostate cancer for about 20 years. >> reporter: but vitamin e may actually increase risk for prostate cancer by 17%. according to results from the so-called select trial of vitamin e and selenium that began in 2001. select researchers followed 35,000 men who were taking one or both of the supplements or a placebo. this type of study is considered the gold standard of medical research. >> i was surprised by the result of this trial. there was a substantial amount of evidence going into select, when it was designed in the early 2000s to suggest that vitamin e or selenium may actually prevent prostate cancer. >> reporter: much of the evidence came from a popular idea at the time, fresh fruits and vegetables have vitamins and anti-oxidants. taking them in a pill form would offer more protection. the trial was stopped in 2008, because the vitamins clearly

weren't helping. researchers continued to monitor the subjects and found an increase in prostate cancer among those taking vitamin e. the final verdict on selenium is not in yet. because vitamins and supplements are not regulated as strictly as medicines, some vitamin e bottles still advertise they promote prostate health. >> consumers should be skeptical about claims that are made on bottles or elsewhere. >> reporter: phil ross stopped taking vitamin e as soon as he heard the latest results. many doctors say others should do the same. robert bazell, nbc news, chicago. up next here tonight, good days in motown. and home movies from mars.

you're about to see a couple firsts here, the first lady michelle obama and the first ever group jumping jack attempt in the backyard of the white

house. it's part of her effort to get kids fit. it was led by our friend al roker, hosted by national geographic kids. 400 kids jumped their hearts out, part of a global effort to break the world record for the most people doing jumping jacks across the globe at once. we thought this needed to be said, these are good days for our friends in detroit. how about them lions, first of all? as one sportswriter put it today, they've been bad for seemingly ever. they beat the bears at ford field last night. now they're 5-0 for the first time since ike was in the white house. the tigers are in the alcs. michigan is 6-0. and the red wings, for heaven's sake, are 2-0. for a town that's had a lot of hardknocks, right now detroit is remembering what success feels like. this is one of the most incredible motion pictures ever produced, and it's from mars. it's actually a three minute series of 309 still pictures put

together. this is the little mars opportunity rover. it took three years to travel 13 miles and recorded the entire journey. we'll put the whole video on our website for you. is it just us or do those martian sand dunes remind you a lot of the jersey shore? either way, this is an incredible scientific achievement. and it's hard to believe that what we're watching is happening on the surface of mars. even though this video has been viewed 2 million times on youtube, it's still new to a lot of americans. a bike race across a south african game preserve, out of nowhere comes the wild antelope. it would be an illegal hit in the nfl. the rider saw it coming at the last minute and was actually saved from serious injury thanks to his helmet. the impact cracked his helmet. he emerged with a concussion and whiplash. the antelope tells a different story back at the den. up next here tonight, how

doctors are making a difference for america's military kids.

tonight's "making a difference" report is a reminder of how important the simple things in life can be,

especially when one of your parents happens to work for the u.s. military, in uniform and a long way from home. our report from nbc's kevin tibbles. >> come in. >> hello there. >> reporter: here at the scott air force base a routine checkup for service members now includes a prescription for reading. >> school books. >> school books, let's read. >> reading is a proven coping mechanism for children in times of stress and tragedy. we know it helps them cope. >> reporter: reach out and read is a program that encourages parents to read aloud to their kids, by providing a new book at every doctor visit. so far, to four million families total, and more than 90,000 children of military families. major doug booser has made recordings of himself so even

when he's deployed, his two boys can still listen in. >> it's good to know your kids are interacting with you even though you're far away. >> you read to me, i'll read to you. >> he reads everything from street signs to books. it's something that's going to serve them every day of their lives. >> reporter: that bond that a book creates between a parent and a child is one that is never broken. >> every time that child picks up the book, he's going to remember the parent. >> reporter: and there are real benefits. many of these books are designed to help kids deal with separation. >> take the time to sit down and read and ask questions. that will help our children be strong readers. >> reporter: little alessandra was just a month old when her father left for iraq. yet thanks to videotapes of him reading, she knows his voice. >> i think she's going to know who he is when we pick him up from the airport. >> reporter: mom janet also takes comfort from story time. >> i would sit in my little rocking chair with her upstairs. i'm like, okay, we're going to

read a book now. >> and listen to daddy? >> and listen to daddy, yes. >> reporter: sharing a book at story time, even if mom and dad are on the other side of the world. kevin tibbles, nbc news, scott air force base, belleville, illinois. >> as we honor the service of everyone in uniform, that's our broadcast on a tuesday night. thank you for being here with us. i'm brian williams, and we hope to see you right back here tomorrow evening, good night. c c cnic ccccc bcccc ccccfocccccurcc cccascncccccceacccc fccccccn c cncc cerc cc pcngcycccccccccccchecccc ckc'sc ccc cuncntcaycmcccccccc cmc jccacccccccccccccccccuc. c canc'mccccerccccccccmac.c cnocenccffccrc ccccccscesccc cbcmocccc ictacccc echccccccc ccac ecnaccmccccc