>> researchers have found a way to make scar tissue into beating heart muscle, but so far only in mice. >> ifill: and we talk with novelists ann patchett and lev grossman about the pulitzer board's decision not to award a prize for fiction this year. >> brown: that's all ahead. on tonight's "newshour." major funding for the pbs newshour has been provided by: ♪ ♪ moving our economy for 160 years. bnsf, the engine that connects us. and by the alfred p. sloan foundation. supporting science, technology, and improved economic performance and financial literacy in the 21st century. and with the ongoing support of these institutions and foundations. and... this program was made possible by the corporation for public broadcasting. and by contributions to your pbs station from viewers like you. thank you. >> brown: once again today, u.s. officials found themselves apologizing for pictures of american troops in afghanistan. they emerged as the u.s. tries to wind down the afghan war and the taliban tries to step up the pressure. >> i've strongly condemned what we see in those photos. >> brown: defense secretary leon panetta spoke just hours after the "los angeles times" published two images. in one, u.s. soldiers and afghan police posed with the severed legs of a suicide bomber-- seen here, partially blurred. the other appeared to show the hand of a dead insurgent, atop the shoulder of a smiling american. the incidents, from 2010, involved members of the u.s. army's 82nd airborne division. they were tasked with identifying dead afghan insurgents through iris scans and fingerprinting. panetta addressed the issue from brussels, where he and secretary of state hillary clinton attended a nato meeting on afghanistan. >> that behavior that was depicted in those photos absolutely violates both our regulations and, more importantly, our core values. this is not who we are and it's certainly not who we represent when it comes to the great majority of men and women in uniform who are serving there. >> brown: the secretary apologized on behalf of the united states government, and he said an investigation has already begun. >> wherever those facts lead, we will take the appropriate action. if rules and regulations were found to have been violated, then those individuals will be held accountable. >> brown: a white house spokesman called the images reprehensible. the times said they were among 18 photos provided by an anonymous soldier. secretary panetta said the military had urged the "times" not to publish the images, fearing the taliban would use them to incite anti-american sentiment. >> i know that war is ugly and it's violent, and i know that young people sometimes caught up in the moment make some very foolish decisions. i'm not excusing that. i'm not excusing that behavior but neither do i want these images to bring further injury to our people or to our relationship with the afghan people. >> brown: the photos were the latest in a series of incidents since the year began, that have made u.s.-afghan relations increasingly tense. in january, video emerged that showed u.s. marines urinating on afghan corpses. in february, violent protests and revenge killings broke out after u.s. troops accidentally burned korans. and last month, u.s. army staff sergeant robert bales allegedly killed 17 afghan civilians in two villages. most were women and children. all of this comes as the taliban steps up its attacks, including last weekend's 18-hour assault in kabul. at the same time, the u.s. and its coalition partners are trying to finalize plans to withdraw combat troops in 2014. for more, we go to craig whitlock, a pentagon correspondent for the washington post and retired army colonel bob killebrew. he served in vietnam and is now a senior fellow at the center for a new american security, a think tank. craig whitlock, what more have you learned about this incident, what the soldiers were doing, what might have led to this. >> we know this unit, the photos were taken in 2010. so a couple years ago, the unit came back later this year but the unit has since redeployed to afghanistan. the army is trying to figure out where these soldiers were. the army says they know who most of them were but it's unclear whether some of them are back in the battlefield, back home or with other units. that's something we're trying to figure out. >> brown: how seriously is the military taking this after several episodes recently. >> i think they're taking it very seriously. as we've seen in this pattern of unfortunate incidents of misconduct since january. that the pen pentagon, the field commanders in afghanistan and the white house convictly apologized. they say they're going to investigate and they do. sometimes it takes some time. we haven't seen the results of the koran burning, the marine video or if discipline has been handed out in those cases so sometimes the investigations can take quite a while. >> brown: colonel killebrew, what do you see in these photos and what steps should the military be taking now? >> well, i think first of all the secretary's statement was right on the mark. we don't do this in warfare. it's deplorable. i think the government, the military, will follow its internal procedures and track this down. i would add two other things, though. one is this happened two years ago in a unit that i know from my own experience has high standards of leadership and training so whatever happened it did not reflect on the unit. it was probably a small group of soldiers, the kind of soldiers that you tell off to do this kind of identification on bodies are typically intelligence soldiers and not direct combat soldiers and the second thing is that it happened two years ago. this is an event that is well behind us now and i wish that it had not come up in that it's going to impede, i'm afraid, our efforts to train up the afghan army and leave a credible force behind us when we get out in 2014. >> brown: you are worried this might have a larger impact or lead people to say... to come to a larger conclusion about discipline or the situation overall there? >> i'm not concerned about that so much as i'm concerned about the impact on our own people here. i think the afghan population has shown itself to understand that these kinds of things happen in warfare. there was, as you know, mass unrest for the koran burning, but when things like this happen in battle or in the fringes of battle, the afghan population seems to take them a lot more calmly than some of us do. i'm concerned about the effect of this on the u.s. will and the u.s. determination to see this war through to the handoff to effective afghan forces in 2014. that's what we have to be working toward. and incidents like this dishearten the american population and cause fears that we're over there doing these things in a widespread way when we're obviously not. >> pelley: do we know whether there's been much reaction in afghanistan yet? >> there hasn't been much reaction in afghanistan yet. i'd like to follow up on what the colonel said. i would point out the "l.a. times" reported that they were given these photos by a soldier from that unit who was concerned about a breakdown in discipline and a lack of leadership. as i mentioned, this unit has gone back to afghanistan. so i don't have inside knowledge of what this brigade has been up to but according to the los angeles angels of anaheim, it wathe "los angeles times," theyd resurface again. >> brown: do we know why they weren't released until now. had they been floating around for two years? and there were more than the two displayed today? >> that's right, the "los angeles times" said they were given 18, they only published two. most were more graphic. the army says they have been investigating this since early march. what happened in the interim is unclear but, again, the difference is that this unit has since gone back to afghanistan and i think perhaps that was the difference here. >> brown: colonel killebrew, we heard secretary panetta say that he wished the "l.a. times" had not gone ahead and published these. do you agree? >> i agree with the secretary. it's a spectacular news story, but it's two years old. this is a time when we need to be building confidence with the afghans. the vast, vast majority of our troops are over there doing selfless service and a thing like this doesn't help us, doesn't help the united states and ultimately doesn't help the afghans. >> brown: craig, i should say first we did instrait "los angeles times" and they weren't able or willing to join us tonight. i'm not going to put you in their seat but what are they saying about why they went ahead with this? >> i think the editor of the "los angeles times" said in their newspaper is they have an obligation to tell readers the truth about what's going on in the war zone, warts and all. certainly "l.a. times," "washington post" and others publish stories about acts of heroism and the good things that the vast majority of members of armed services do over there but we have an obligation to public when misconduct happens and that's unfortunate but the public deserves to know the reality of war. and sometimes the secretary of defense said wars are ugly and violent and people need to understand that, too. >> brown: in the meantime, craig, the military is preparing for possible reprisals? they clearly voiced concerns about it. >> the pentagon said they are taking additional measures to protect u.s. troops and they're worried this could lead to additional risk for soldiers in the front. >> brown: all right. craig whitlock and colonel bob killebrew, thank you both very much. >> ifill: still to come on the "newshour": the push for the hispanic vote; shareholders take a stand; a fix for damaged heart muscles and no winner for the fiction prize. but first, with the other news of the day, here's hari sreenivasan. >> sreenivasan: the syrian military escalated attacks on rebel areas today, despite the government's claim that it is adhering to a cease-fire. in the central city of homs, amateur video showed large plumes of smoke rising. mortar rounds and shells rained down on rebel-held sections. elsewhere, two vehicles carrying u.n. observers were surrounded by thousands of anti-government protesters near damascus. then, gunfire erupted as syrian security agents fired on the crowd, and the observers were forced to flee. in brussels, belgium, u.s. secretary of state hillary clinton condemned the violence. >> it is obviously quite concerning that while we are deploying these monitors pursuant to a security council resolution that confirms our commitment to kofi annan's six point plan, the guns of the assad regime are once again firing in homs, idlib and elsewhere and syrians continue to die. >> sreenivasan: clinton said syria has reached a turning point, and she warned of new pressure on the government, unless it relents. at least 22 soldiers died today in growing border fighting in east africa, between sudan and south sudan. there have been almost daily battles since south sudan seized the oil town of heglig, last week. sudan today demanded an immediate withdrawal. south sudan claimed its independence last summer, but the border was never settled, and the two sides never agreed on sharing the region's oil wealth. in the u.s. presidential campaign, president obama and mitt romney traded criticisms over economic policy. the president traveled to the swing state of ohio, and he charged that republicans are dead wrong on how to build a recovery. he spoke to a community college in elyria, near cleveland. >> in this country prosperity doesn't trickle down. prosperity grows from the bottom up and from the strong middle class out. ( applause ) that's how we grow this economy ( applause ) and that's why i'm always confused when we keep having the same argument with folks who don't seem to remember how america was built. >> sreenivasan: mitt romney offered the republican answer this afternoon, in charlotte, north carolina. he accused the president of pitting americans against each other to divert attention from his own failed policies. >> one of the things that is most disappointing to me in our president has been that over the last 3.5 years he has engaged in constant efforts to divide americans. and to find blame in one after another. and each day if there's a problem with some group of americans who much be responsible for it. never saying he's responsible for the mistakes he's made and policies that made it hard for businesses to start and for people coming out of school to find a good job. >> sreenivasan: romney also said today he would clean house at the secret service. he called for firing 11 agents who allegedly used prostitutes in colombia, ahead of a presidential visit last week. this evening, the secret service announced three of the agents are leaving its employ. it says the investigation will continue. wall street gave back some of its gains of the last few days. the dow jones industrial average lost more than 82 points to close at 13,032. the nasdaq fell 11 points to close at 3,031. a retired couple in southern illinois has claimed the final share of last month's record mega millions lottery jackpot. merle and patricia butler came forward today, and took home a lump sum of $111 million, after taxes. butler said even when he matched the winning numbers to his $3 ticket, it took a few moments for the realization to sink in. >> after i looked at it for a couple minutes, i turn to my wife who was right there with me and i says, "we won," and she kind of looked at me funny and i says "no, we've won." then she started giggling and she giggled for about four hours, i think. >> sreenivasan: the overall jackpot totaled $656 million. the other winners in kansas and maryland have chosen to remain anonymous. the winningest coach in women's basketball is stepping down. pat summitt announced today she will not be back as head coach at the university of tennessee next season. instead, she'll become head coach emeritus. summitt is 59. she announced last august that she has early onset alzheimer's. during 38 seasons at tennessee, her teams won 1,098 games and eight national championships. long-time television host and producer dick clark died today, after a heart attack, at a hospital in santa monica, california. he was dubbed "the world's oldest teen-ager", and became a tv fixture across several generations. >> live from philadelphia, it's time for america's favorite dance party. "american bandstand." >> sreenivasan: dick clark hosted that famous dance party >> this one's called "rock around the clock." >> ♪ one, two, three o'clock, four o'clock rock. >> sreenivasan: clark's clean shaven, suited image helped introduce rock and roll into the livingrooms of millions of >> this is sam cook singing, "you send me, darling, you send >> sreenivasan: clark used his fame to create an empire-- producing awards shows and hosting game shows, including the "the $25,000 pyramid." >> happy new year 2001! >> sreenivasan: and since 1972, he helped the country count down the new year. he continued to host "the new year's rockin' eve," even after he suffered a stroke in 2004 that affected his ability to speak and walk. >> my speech is not perfect, but i'm getting there. >> sreenivasan: dick clark never liked to say goodbye. instead, he ended every broadcast with his signature salute: >> i'm dick clark. so long. >> sreenivasan: dick clark was 82 years old. those are some of the day's major stories. now, back to gwen. >> ifill: along the campaign trail, democrats and republicans take note of the census numbers and plot a new path to victory. >> soy barack obama, y apruebo este mensaje. >> ifill: it's not a coincidence that president obama has begun speaking spanish. as the general election campaign takes shape, democrats and republicans are competing for the support of the nation's fastest growing demographic group, latino voters. the "newshour's" vote 2012 map center found in 2008 hispanic voters represented large percentages of voters across the southwest and florida. but the map is much bigger than that. both campaigns are competing heatedly in at least three critical swing states: nevada, colorado and florida. latinos made up 9% of voters overall in 2008, and they chose mr. obama over john mccain by more than two-to-one. seeking to nail down that edge, the obama campaign launched a series of new spanish language ads today. but the g.o.p. is also in the hunt. the republican national committee appointed hispanic outreach directors in those states this week as well as in virginia, new mexico and north carolina. >> los estados unidos representa libertad, oportunidad, donde todo es posible. >> ifill: romney launched his appeal in florida during january's republican primary. this ad was voiced by romney's son craig. >> soy mitt romney y apruebo este mensaje. muchas gracias. >> ifill: but the presumptive republican nominee has a significant gap to close. a pew research center poll released this week showed the president leading romney 67% to 27% among hispanics. until now, much of the debate has centered on immigration issues, but both sides are focusing on the economy and on education. with the obama campaign highlighting support for pell grants that helped nearly two million hispanic students attend college. and romney expressing mild support for senator marco rubio's version of the "dream act" which would allow children of undocumented immigrants to remain in the u.s. legally. during the primary campaign, he pledged to veto another version of the bill that granted citizenship. for more on the intense competition for hispanic voters from coast to coast, we are joined by representatives from both major parties. senator bob menendez of new jersey, former chairman of the democratic senatorial campaign committee. and bettina inclan, director of hispanic outreach for the republican national committee. senator, start by telling us how critical the latino vote is this year. >> well, i think as it was four years ago, the latino vote is critical in some of the key states that will be battleground states that you previewed, some of them. but also in states that people may not think of as battleground states in terms of latinos but virginia, north carolina. this is an all-out effort by the obama campaign to reconnect with latino voters, to remind them what's important in this election, what's at stake for them, to talk about an administration that has worked hard from making health care affordable for nine million latinos who didn't have health care to looking at changing the economic realities of latinos in the country over $800 million in the president's small business jobs act, that went to hispanic-owned businesses. to changing the realities of where we were in the disaster... economic disaster we were left in 2008 and having a hispanic unemployment drop drama khr-t i. still more work to do but moving in the right direction. so it's going to be a critical vote in this election and one the president enjoys an advantage but is not taking for granted by any steph of the imagine nation. >> ifill: miss inclan, the republicans aren't taking it for granted either. what issues do you hope will drive latino voters to switch allegiances. >> the latino vote, the hispanic vote, is very important. senator menendez talk about how they make key constituencies in major swing states. we've hired six state directors, in florida, north korea next, virginia, colorado, new mexico and nevada and we'll be having a national outreach program to connect with even more voters across the country. the number one issue going to be the economy and he mentioned a little bit the unemployment for the hispanic community is unacceptable. it's two points higher than the national average. there's more hispanic children living in poverty