evolve out of this. maybe the things i've done and am still doing will still shine a light and give them hope at some point. >> the following is a cnn special report. ♪ ♪ are you sure that your husband got shot? >> yes. he was hit in the head. >> a brutal killing on a glistening lake. >> you saw your husband get shot and thrown from the jet ski? >> yeah. >> were they caught in a cross fire? >> it's a war over there. two cartels fighting each other for control. >> drug deal gone bad?

or was this cold-blooded murder? >> there has been a lot of suspicions based on some of her behaviors. >> tonight, a cnn special report. "murder in mexico: what happened at falcon lake." >> reporter: it's late afternoon in mccallen, texas. air operations are about to begin. >> there are some areas west of mcallen along the southwest border that are completely out of control, in my opinion. >> reporter: captain stacy holland and his team from the texas department of public safety are trying to stop drug smugglers from crossing from mexico into the u.s.

>> right there, right there. one guy's gotten out. one guy's gotten out into that house. >> reporter: they are also trying to stop the violence of a full-scale drug war from spilling north. >> are there parts of this border that you would be basically lawless or run by the cartels? >> absolutely. ♪ >> reporter: smack in the middle of this 21st century version of the wild west, two young americans, david hartley and tiffany young, just teenagers when they fell in love. >> we started dating in '98. the summer of '98, and dated for quite a while before we got engaged in 2001 and married in 2002. >> what took so long? >> we were 18. >> reporter: they wound up here, in the mexican border town of reynosa, jut south of mcallen. he was a district manager for an oil company.

>> it was a blessing to us and our marriage. yeah. we were -- that's where we truly grew as a couple and had adventures. >> reporter: when the hartley's first arrived here this peaceful town was a perfect place for the young couple to live, but slowly it became more and more violent. there is a war in reynosa. two drug cartels battling for turf. the zetas, a rogue band of former military, are trying to push out the gulf cartel which has smuggled drugs across the rio grande for decades. killings of constant. tiffany and david hartley learned firsthand. mexican police were not to be trusted. for instance, he was coming home from the bank after cashing our rent check and police pulled him over, followed him from the bank. pulled him over. had him step out and punched him

in the face and stole his money. >> reporter: david, she says, saw someone get shot on the street. did you sense it was getting more dangerous? >> you could. yeah. you could sense it. you'd hear more about it. >> reporter: what did they look like? describe how you would pick out a cartel member? >> their trucks at that time had their name. >> the zdg, or a z on it for the zetas. they had actually marked their vehicles with their name and who they were. >> reporter: david convinced his company to allow him at least to live on the american side of the border in mcallen. soon afterwards, the company told david he was being offered another transfer, back home to colorado. to his mom that was a blessing. >> they were going to be home that next week looking for a house to move into. i mean, we were excited about

them coming home. >> reporter: but there was some unfinished business. one last adventure david had long talked about, but never got around to. he had heard of a church partially submerged in falcon lake on the mexican side in an abandoned village called old guerrero. perfect for a couple who loved their jet skis and loved adventure. >> i'm just like, okay. let's go see it. >> reporter: had they asked local law enforcement would have warned them about pirates on the lake. had they asked, captain stacy holland would have told them not to go. >> we don't recommend going into mexico on the side of the lake, but it's perfectly well with -- well within your rights, but we just want you to be aware that that threat is out there, and it's very real, and you should take it seriously. >> reporter: it was a thursday and david hartley called home.

>> they were excited to go have one last big ride on their jet skis before they come back to colorado, and colorado doesn't have the water, what they have around there. so, yeah. one last time to have a good time. >> reporter: it is a two-hour drive to falcon lake from mcallen. a trip documented by a traffic stop halfway there, in a town called rio grande city. something to the police looked suspicious. >> right, right. >> reporter: it looked like somebody might be stealing some jet skis. >> the trailer had expired tags. troopers let them go with just a warning, but this videotape would become part of the evidence for what was about to happen. >> you come to any strange area in the united states, mexico border, and you go to

sightsee, and you're a tourist, stop in and talk to the locals. you know? find out what's going on in the area. if they'd have stopped in here and i had known they were going on jet skis, that's total no-no in falcon. >> reporter: up next, jet skiing into the heart of a drug war. ♪ 800,000 hours of supercomputing time, 3 million lines of code, 40,000 sets of eyes, or a million sleepless nights. whether it's building the world's most advanced satellite, the space station, or the next leap in unmanned systems. at boeing, one thing never changes. our passion to make it real. ♪ our passion to make it real. could save you fifteen percent or more on car insurance. everybody knows that. well, did you know you that former pro football player ickey woods will celebrate almost anything? unh-uh.

number 44... whoooo! forty-four, that's me! get some cold cuts... get some cold cuts... get some cold cuts! whooo! gimme some! geico. fifteen minutes could save you fifteen percent or more on car insurance. whoo! forty-four ladies, that's me! whoo...gonna get some cold cuts today! just take a closer look. it works how you want to work. with a fidelity investment professional... or managing your investments on your own. helping you find new ways to plan for retirement. and save on taxes where you can. so you can invest in the life that you want today. tap into the full power of your fidelity greenline. call or come in today for a free one-on-one review. painstakingly engineered without compromise. to be more powerful... and, miraculously, unleash 46 mpg highway.

an extravagance reserved for the privileged few. until now. hey josh! new jetta? yeah. introducing lots of new. the new volkswagen jetta tdi clean diesel. isn't it time for german engineering? feel like a knot. how can i ease this pain? (man) when i can't go, it's like bricks piling up. i wish i could find some relief. (announcer) ask your doctor about linzess-- a once-daily capsule for adults with ibs with constipation or chronic idiopathic constipation. linzess is thought to help calm pain-sensing nerves and accelerate bowel movements. it helps you proactively manage your symptoms. do not give linzess to children under 6, and it should not be given to children 6 to 17. it may harm them. don't take linzess if you have a bowel blockage. get immediate help if you develop unusual or severe stomach pain especially with bloody or black stools

the most common side effect is diarrhea, sometimes severe. if it's severe, stop taking linzess and call your doctor right away. other side effects include gas, stomach-area pain and swelling. bottom line, ask your doctor about linzess today. [ squeaking ] [ water dripping ] visit tripadvisor hawaii. [ whistling ] with millions of reviews, tripadvisor makes any destination better.

>> reporter: along the texas-mexican border there's little doubt. drugs and human smuggling are big business. very big. >> their operational plans are very good, and the one thing about these cartels is that they're ruthless and violent, but they're not stupid. >> reporter: captain stacy holland of the kpags department of public safety says his proof is in his videos, captured night after night by the thermal imaging camera mounted underneath his helicopter. over the last few years, there's been more violence and most disturbing of all to holland,

more coordination, lookouts, even reconnaissance in smuggling. >> one thing you have to understand is how well coordinated this is and what the level of scouting and planning and organization is. >> right coming up. >> reporter: these videos of chases at first made no sense. >> you getting a shot of this? >> yeah, i got it. >> reporter: drug runners caught in the u.s. and then racing back to mexico. >> coming up to the river. >> reporter: their stolen vehicles hurled full speed into the rio grande. >> oh, my god. splash down. >> reporter: at first, law enforcement believed these were desperate attempts to escape. then they began to hear radio traffic. coordinates. >> going to be splashdown. the truck there. >> right there. oh-oh! >> in the water. >> that's a recovery team. >> just a recovery team? recovery team right there. >> reporter: the cartels even

began organizing search and rescue teams and suddenly the videos made sense. drug smugglers hurling their stolen vehicles back into the rio grande were doing it for one reason. to protect their dope at all costs. >> all units we had a splash down. we have a splashdown in the river. >> they don't mind losing the truck into the river. at the end of the day if they can recover 2,000 pounds of narcotics with an estimated street value between 600 and 800,000 that's what they're going to do is protect that inventory. >> it's going under. suspect just about on my side. >> reporter: inside mexico, the army has visibly taken over much of the security in border towns. local mexican police who are not corrupted by the cartels are targets of them. thousands killed. and americans have been targets, too.

>> you know, i almost think that we're flying over tribal pakistan, the way you describe this area. are you surprised or are you hardened to the fact that most of america doesn't realize this is going on? >> you know, it does amaze me, and maybe it's because i'm exposed to it so much working on the southwestern border, but we're in a war. we're in an engagement with an enemy that's like no other enemy we ever faced before. you have to combat these people with some of the same tactics that they employ on you. if you asked me ten years ago would we be doing some of the missions and tactics that we're doing today, i would have said absolutely not. >> reporter: since 2004, the state department says 200 americans have been killed in mexico and nearly all caught up in the vicious firefights between rival drug cartels. it is no different even along this peaceful 28-mile long lake straddling the u.s.-mexican border two hours north of mcallen.

>> we've had along the border, shootings. we've had along the border, murders, home invasions, burglaries, rapes. all types of crime where it's associated with what i call spillover violence. >> reporter: siggy gonzalez was the sheriff in zapata, texas, and oversaw the investigation of the hartley incident. he has retired since our interview. >> i remember when i started as a deputy sheriff back in the 1970s, where this was used for drug trafficking. human trafficking. being used like that forever. >> reporter: and lately, even before the hartleys' trip to falcon lake, gonzalez says a new threat has emerged. pirates. >> totally inaccurate. definition of piracy a lot

different than what i know it to be. had one robbery on the lake totally. >> reporter: robert speedy colette who owns a fishing lodge here admits he's been stopped by drug cartel members but he also bristles at news reports of piracy and danger. these reports have decimated his business on the lake, which he insists is safe, as long as you know the rules. >> it happened to me. i didn't run. they boarded. they found out i wasn't a threat, and i was released. never robbed. never took a penny from me. they did not -- my wallet was in my glove box. i had $1,100 in my wallet. my clients were pretty wealthy people. my clients were interpret -- pretty wealthy people. nothing ever happened to them. >> reporter: in the air over falcon lake, stacy holland says the texas department of public safety was already advising boaters on falcon lake to be very careful. >> just a warning to let people know that this threat is out

there and it's very real and that we've had documented cases of pirating. so it's mainly for situational awareness, and, you know, we don't recommend going into mexico on this side of the lake. >> reporter: tiffany hartley says she had heard about troubles on falcon lake, but she and david had been there once before and things were fine. she never thought that somehow anything could happen. >> we hadn't heard of anything for a while and we were just there in august. enjoyed three, four hours that day on falcon lake. >> reporter: after all, it was so sunny. so calm. so perfect for one last ride. >> i told him, please, don't shoot. please, don't. >> reporter: in an instant, tiffany hartley claims she and david were caught in a war zone. >> are you sure that your husband got shot? >> yes.

yes, he's hit in his head. he was thrown off the jet ski and i couldn't pick him up to get him on mine. oh yea, that's coming down let's get some rocks, man. health can change in a minute. so cvs health is changing healthcare. making it more accessible and affordable, with walk-in medical care, no appointments needed and most insurance accepted.

minuteclinic. another innovation from cvs health. because health is everything. they take us to worlds full of heroes and titans. for respawn, building the best interactive entertainment begins with the cloud. this is "titanfall," the first multi-player game built and run on microsoft azure. empowering gamers around the world to interact in ways they never thought possible. this cloud turns data into excitement. this is the microsoft cloud.

on beautyrest and posturepedic. save up to $300 even get three years interest-free financing on tempur-pedic. keep more presidents in your wallet. sleep train's presidents' day sale is on now! ♪ your ticket to a better night's sleep ♪

>> reporter: david hartley had always been interested in visiting the sunken church in falcon lake. on thursday morning, september 30th, 2010, a week before he and his wife would move home to colorado, david decided they would go. >> did you know then what you must know now, that there had been several attacks on that lake? that fishermen don't cross into mexico on that lake anymore. >> we did know there were attacks. we didn't know where exactly. >> reporter: you had no worries whatsoever when you took those jet skis out? >> no idea. >> as tragic as this is what i think i'm hearing from you is what the hartleys did was incredibly stupid. >> incredibly. >> reporter: fishing guide and resort owner speedy colette says

business on the lake has taken a beating since the hartleys made what he called a stupid trip to see a sunken church. he is sick of the media attention and insists that the lake and the fishermen are completely safe as long as they follow these unwritten rules. >> this is not a jet ski lake. never a jet ski seen. they come, they show up on jet skis that they don't see, then they try to approach them and stop them, because it's a war over there. two cartels fighting each other for control, and they don't stop. they take off running. >> colette agreed to take us to old guerrero, eight miles into mexico, into what he describes as a drug war, to show us just how safe it really was. but before he even passed the channel marker dividing the u.s. and mexican border, speedy made us promise not to raise our camera, not to raise any suspicion and told us there's no doubt how jet skiers would look

following this same path, like drug smugglers. >> only people with jet skis are involved with dope. >> right. >> reporter: clearly nervous, colette barely slowed down as we approach the church tiffany and david hartley visited on september 30th. he turned the boat and gave us 30 seconds to take the pictures at the exact spot tiffany hartley said they had stopped. >> this is the last place they came to at the old guerrero church. they took pictures on the front step, according to tiffany hartley. and they set down this channel to head back, and it was about five minutes into their voyage when they were approached by the boats. in an instant, the man who told us this lake was safe was again speeding away from mexico 70 miles an hour. the same path the hartleys were on when tiffany says the attack began. >> there's a boat on our left

and two on our right. on kind of towards the land, we're kind of in the middle of the lake. and then that's when he motioned that we needed to go. >> reporter: did you see something in his eyes that said, this could be serious? >> i could just tell by his body language. you know, i saw him and he was just kind of -- we got to go. like, this is serious, but he stayed behind and stayed between me and the boats. >> reporter: you think, protecting you? >> hmm mm. >> reporter: it was now a chase. tiffany says her jet ski was going at least 65 miles an hour. they were racing for the other side, for the u.s., for safety. i mean, were you scared? were you frightened at that moment? >> oh, oh my gosh. yeah. >> reporter: you thought these guys are coming after us? >> uh-huh. >> reporter: three boats closing from two directions, but not

catching up. tiffany thought they would outrun them until she heard the shots. you heard shots. boom, boom, boom? >> you could hear them, you could feel them. you could feel them flying by you. until i saw the two next to me. that's when it came really clear how close they were. >> reporter: and you saw your husband get shot and thrown from the jet ski? >> yeah. >> reporter: tiffany says she circled back as the three boats encircled her. david was face down, she says, floating, when she jumped into the water in a failed attempt to save him. turning him over, she realized there was nothing to save. why did you turn around? >> he's my husband. he's my love. he's my life. he's everything to me. and once i saw him flying off, i didn't know where he was shot,

but i knew it couldn't have been good and there was no way i was going to not go and try to help him. >> reporter: can i ask you where he was shot? >> in the back of the head, but it came out in the front. the forehead. >> reporter: did you know immediately -- >> yeah. he wasn't -- he wasn't there. he was gone. you know, yelling for help and looking for anybody who would help me, but knowing there was not going to be anybody. >> reporter: but somebody was still there. she claims standing over her, a gunman in one of the boats. >> reporter: did you think, this is it? >> uh-huh. i told him, please, don't shoot. please, don't. >> reporter: in a moment of apparent confusion, hartley says she saw her chance to flee. >> the gun would be on me, and

then he'd take it off and then he'd put it back on me. it's like he didn't know what to do with me. do i shoot her? do i not? that's when they left to go meet the other boats. >> reporter: racing towards the u.s., she passed the boat slip where she and david launched from less than an hour earlier. the boat's in pursuit. she spotted a man here watering his lawn, yelling, asking if he spoke english. that man would help a distraught tiffany hartley place this 911 call. >> are you sure that your husband got shot? >> yes. he was hit in his head. >> okay. >> yes. >> was he thrown off the jet ski? he's in the water some place? >> yeah. he was thrown off the jet ski and i couldn't pick him up to get him on mine. he was just too big. >> what is your name? >> tiffany hartley. >> reporter: when the story broke it was almost

unbelievable. americans being fired on? a jet ski chase? a narrow escape and a dead husband whose body has yet to be found. >> when you are describing this horrific events, you seemed somewhat detached. the victim, at least in the eyes of some, was about to come under suspicion. i'm either away from my desk or on another call. please leave a message and i'll get back to you just as soon as i'm available. thank you for patience at this busy time. join princess cruises for stargazing with discovery at sea. enjoy cruises from $499 during our 50th anniversary sale. call your travel consultant or 1-800-princess. princess cruises. come back new. scourge of 20th century city life. raiser of blood pressure. disrupter of supply chains.

stealer of bedtime stories. polluter. frustrater. time thief. [cars honking] and one day soon, we'll see the last one ever. cisco is building the internet of everything for connected cities today, that will confine the traffic jam to yesterday. cisco... ...tomorrow starts here. meet thsuperpower.ewest energy surprised? in fact, america is now the world's number one natural gas producer... and we could soon become number one in oil. because hydraulic fracturing technology is safely recovering lots more oil and natural gas. supporting millions of new jobs. billions in tax revenue... and a new century of american energy security. the new energy superpower? it's red, white and blue. log on to learn more. i have $40,ney do you have in your pocket right now? $21. could something that small make an impact on something as big as your retirement?

i don't think so. well if you start putting that towards your retirement every week and let it grow over time, for twenty to thirty years, that retirement challenge might not seem so big after all. ♪

>> reporter: from almost the very beginning after the attack, tiffany hartley seemed to be everywhere telling her story. >> i think it would be difficult for anybody in my situation, and i know, you know, there's been stories out there before, and people question. but i know what i know. i know what i saw. >> reporter: not only interviews with local television stations but networks. on the "today" show. >> how close did these people come to you? can you describe them to me? >> honestly, looking at the barrel of the gun is all i saw. >> reporter: the cbs morning news. >> we never really had that feeling that something was going to happen that day. >> reporter: but word began to leak out even from mexico that her story was being doubted. >> so she kept on coming this way. >> reporter: the zapata county sheriff, siggy gonzalez was the first american law official to speak with her.

>> it seems something made up. seemed like a story out of the comic books. >> it's hard, because -- >> reporter: but tiffany hartley is insistent on telling her version of what happened. here with cnn's anderson cooper. >> you were meeting with mexican investigators for much of today. did you get the feeling that they believed you or they didn't believe your story? >> no, i do believe that they believe my story. i mean, they -- we had people from the state and then also federal. so everyone has come together to get my statement and that's why it's taken so long. just so everybody has the statement. everybody can't say that they don't have it. >> reporter: and while texas authorities mounted an intensive search for any evidence that could back up her story, tiffany hartley's behavior, detached, showing little emotion, ramped up gossip and suspicion that somehow she was not telling the truth.

>> i think that there has been a lot of suspicions based on some of her behaviors and interviews she did shortly after the murder of her husband, which raised doubt in people's mind. >> reporter: fred burton's firm provides security information for companies worldwide, including information on drug cartels operating along the u.s.-mexican border. >> anybody that's an outsider that goes into that area is viewed as either working for another cartel or a possible informant for a government agency. >> this is the boat ramp. this is the area where she -- where she came to seek help. >> reporter: sheriff siggy gonzalez now trying to investigate a crime in another country was fending off calls from reporters asking if the hartleys themselves were drug runners or if david hartley was working with the cartel. speculation began to swirl that tiffany hartley killed her

husband for insurance money or even that tiffany hartley was seeing another man. >> people still have a hard time believing you. does that hurt you? >> some days. other days -- they don't have room to judge. i mean, they don't know me. they don't know my husband. they weren't there that day. so really they have no room to judge me. >> reporter: with television and newspaper attention still at viral levels, authorities in texas were trapped. they could dispatch all the boats and helicopters they wanted, but law enforcement in mexico was still in charge. and what happened next in mexico showed just how difficult getting any answers would be. >> one mexican detective did try to find out what happened to david hartley.

but his head was severed from his body and his decapitated head was delivered to the mexican army here in a border town. his name, rolando viegas. his suspects, brothers who lived near the half submerged church in mexico, old guerrero. it's unclear if he went looking for them, but only a few days after he identified the brothers by name, the detective was dead. a clear warning for any law enforcement not to follow in his footsteps. >> one detective did try. >> we understand that he did try, yes, and -- >> reporter: he was executed. >> i asked if he was perhaps executed because of being involved in drug trafficking or because of this case, and i was told by the source that they thought he was killed because of his involvement in trying to assist in the investigation of the case.

>> reporter: a case gone cold. but new evidence is about to emerge from falcon lake.

get to the terminal across town. are all the green lights you? no. it's called grid iq. the 4:51 is leaving at 4:51. ♪ they cut the power. it'll fix itself. power's back on. quick thinking traffic lights and self correcting power grids make the world predictable. thrillingly predictable. but i've managed.e crohn's disease is tough, except that managing my symptoms was all i was doing. and when i finally told my doctor, he said humira is for adults like me who have tried other medications but still experience the symptoms of moderate to severe crohn's disease. and that in clinical studies, the majority of patients on humira saw significant symptom relief.

and many achieved remission. humira can lower your ability to fight infections, including tuberculosis. serious, sometimes fatal infections and cancers, including lymphoma, have happened; as have blood, liver, and nervous system problems, serious allergic reactions, and new or worsening heart failure. before treatment, get tested for tb. tell your doctor if you've been to areas where certain fungal infections are common, and if you've had tb, hepatitis b, are prone to infections, or have flu-like symptoms or sores. don't start humira if you have an infection. ask your gastroenterologist about humira. with humira, remission is possible.

♪ >> reporter: on falcon lake there has been no sign of david hartley's body, his jet ski, anything that could prove his wife's story, that her husband was shot to death by mexican drug smugglers. the beheading of the one mexican

detective, willing to at least try to solve the crime, has dealt the hartleys another blow. you feel right now there's people in mexico, maybe even police in mexico, who won't say what happened to david. >> yes. >> reporter: because they're afraid. >> yes. if you have threats against your loved ones, if you don't know if they're going to come home, i mean, that's a fear that i can't imagine. i don't want to imagine. that's why it's like, this has to stop. >> reporter: without any clear answers from mexico, the hartleys have turned to intelligence sources north of the border who can try to explain why the couple was targeted. former intelligence official fred burton has been studying a turf war in mexico between two drug cartels. a former band of military guards called the zetas and the more

traditional gulf coast cartel. >> what most people don't realize when you're looking at the border is that there are certain portions that are not controlled by the mexican government. and the area of falcon lake was directly controlled by the zetas, and this was a very strong smuggling corridor for them. >> reporter: so you believe this was mistaken identity? >> clearly, all evidence indicates that this was a case of mistaken identity based on the tactical intelligence i've seen surrounding the case. >> the most likely scenario is, david and tiffany hartley had wandered into a drug war and were mistaken as the enemy. >> reporter: zapata county sheriff siggy gonzalez believes the hartleys not only wandered into a war but had arrived on

the mexican side of falcon lake at the exact moment a cartel was about to move a large amount of marijuana. up on a bluff, the spotters, his sources told him, caught the first glimpse of a possible glitch in the drug deal. >> that area is an area that's notorious for crossing or storing of thousands of pounds of marijuana. we've known that for a long time. that information is information that i have relayed to federal officials, you know, i mean, local, state officials. we're all aware that that area is used as an area that they hide tons of marijuana in. >> reporter: so based on your sources and your intelligence, when they began to encroach on what would be a drug deal, they were looked upon as potentially -- >> as threats. yes. as threats. and that's why they were given instructions to go ahead and shoot at them. >> reporter: the sheriff now tells cnn that eyewitnesses have come forward to him.

witnesses he says who claim to know what happened here that day. they describe a military-style attack. three boats, several shooters, and hundreds of rounds being fired at two jet skiers. >> the shot that killed david hartley was an unlucky shot. >> reporter: the sheriff now believes the killers were instructed to kill tiffany hartley, too. what happens next, he says, is a scenario he has put together from three witnesses on the mexican side of the lake. one source in mexico and at least one witness who told cnn that he saw a high speed chase on the u.s. side. a boat chasing a girl on a jet ski. it is clear that one of sheriff gonzalez' sources was involved in the attack itself. >> so they were given the instructions to go ahead and shoot and kill her also. but she was able to escape. they also say, she was able to get away from us, and we kept shooting at her to hit her, but

she kept zig-zagging and we were not able to hit her. she says she was zigzagging when she was coming across, being chased by the boat into the united states. and of course, there is a witness that corroborates that also. >> reporter: the eyewitness who was standing here at the time is still too scared to show his face on camera, but is telling cnn now that he did witness not only tiffany hartley on her jet ski, but the boat chasing her right there as they came into this inlet, in american waters chasing tiffany hartley almost up until the time she came ashore. >> it's too many people involved for it to be a conspiracy she'd be paying people off. >> reporter: the sheriff believes tiffany's story and his sources and witnesses confirm it. you don't believe the hartleys were involved in drugs? >> no. >> you don't believe there is an insurance scam going on? >> where's the body? >> reporter: you don't believe tiffany hartley herself may have executed her husband. >> i don't think so.

>> reporter: and now even more evidence tiffany hartley is telling the truth. a surveillance photo taken that very afternoon, one hour after the attack. >> if you notice there on the front of the boat, you see bundles of marijuana there. >> reporter: it shows a small boat and a group of men, one in a green shirt, one shirt black, fitting the description given by tiffany hartley, and what sheriff gonzalez says is a bale of marijuana in the bow. it's information the mexican sheriff had from the very first day. >> reporter: sheriff, i've got to ask you, is that possible that mexico is going to find, catch and adjudicate the killers in what is a lawless part of mexico? >> i really cannot answer that, but i can tell you this, based on their past record, i think they have a -- somewhat of a zero solvency rate and a zero conviction rate.

>> reporter: there is one more piece of evidence. a small blood spot on the life jacket tiffany hartley wore the day she says her husband was shot. the blood is from her husband. sheriff gonzalez says a dna test confirms it, but even the dna match remains just one more piece of an unsolved puzzle. there is still no body, no jet ski. is tiffany hartley even telling the truth? or is there another secret yet to be told? meet the world's newest energy superpower. surprised? in fact, america is now the world's number one natural gas producer... and we could soon become number one in oil.

because hydraulic fracturing technology is safely recovering lots more oil and natural gas. supporting millions of new jobs. billions in tax revenue... and a new century of american energy security. the new energy superpower? it's red, white and blue. log on to learn more.

i moved our old security whsystem out here? to see if it could monitor the front yard. why don't you switch to xfinity home? i get live video monitoring and 24/7 professional monitoring that i can arm and disarm from anywhere. hear ye! the awkward teenage one has arrived!!!!

don't be old fashioned. xfinity customers add xfinity home for $29.95 a month for 12 months. plus for a limited time, get a free security camera call 1800 xfinity or visit comcast.com/xfinityhome. ♪ >> reporter: after all the searching, all the investigation, texas authorities say they could not find the body of david hartley. >> where is the body? >> the body was disposed of. there is no body. >> this is the international boundary. >> yeah. >> reporter: in his office in texas, county sheriff siggy

gonzalez says he knows for a fact that david hartley will never be return to the united states for burial. do you know how? >> yes. four different sources with different agencies have come forward and told us how they disposed of the body. >> reporter: those sources say the body of david hartley was placed in a barrel and burned. in colorado where she now lives, tiffany hartley refuses to believe her husband's body will never be returned. >> it's passed my mind, but i'm not willing to accept it in my heart. i know my god and he's bigger than any one and any thing, and he wants justice just as much. >> reporter: the cold reality, however, seems very different. on her website, "bring david home.com" there were plenty of people who still believe she's a

suspect. she continues making statements perceived as odd. what she told me, that god was involved in this traffic stop the day david was killed. to help her. tiffany, you just said from that moment i knew god's hand was in our lives that day. >> people probably think that -- well, how? >> reporter: i'm thinking that right now. >> because i believe he had us being pulled over to prove, because he knew that i would be judged, that i would be questioned that day for what happened. >> reporter: even though dna proved david's blood was on tiffany's life jacket, questions persist. where was the camera they used to take pictures of old guerrero? why wasn't there far more blood evidence? >> the jet ski -- >> the jet ski was destroyed. my understanding, the jet ski was taken apart. that parts that would float were

burned and buried afterwards. and the parts that would not float were just thrown into the lake and of course, they sunk. this is coming in from mexico. >> reporter: the sheriff believes hartley's story but may never be able to prove it. david hartley's mother can barely control her emotion. >> what happened to david and tiffany was an act of terror. plain and simple. it was a senseless violence, but it was an act of terror. and that is not going to end at the border. it's over here already. >> reporter: and for tiffany herself, it is even more troubling. >> reporter: do you think your husband is a victim of, in a way, politics? >> i would say a victim of terrorism. politics. and -- the way of life of mexico.

and the politics -- i think there's too many connections between u.s. and mexico, too much money going back and forth. >> reporter: connections you mean in a criminal way? >> in a money way. i think it's all money. >> reporter: in the air over border country, captain stacy holland says the financial stakes are so high for the drug cartels, that money takes precedence over everything else. >> so what the states faced with and the nation really is an aggressive narcotics smuggling ring, cartel, their interest lies in their inventory. that's what they're going to protect. and they're going to do whatever means necessary to protect their inventory. >> reporter: in the case of david hartley, that includes the cartel inflicting its own investigation and its own brand of justice. security expert fred burton has followed the case closely.

>> it's my understanding that the individuals that were involved with the killing of mr. hartley were in essence picked up and killed by the zetas themselves. >> reporter: the killers were killed? >> correct. the killers were killed by the organization, because, remember, this is bad for business. >> reporter: if the killers are dead, tiffany hartley may never be able to prove what happened. she knows how many people still don't believe her story. and she and david were just sightseeing, that she tried to save him. that she outran boats with gunmen firing at her, in interviews she remains unemotional. that, too, in the eyes of many has made tiffany hartley suspect. >> people don't see me at night when i go to bed. they don't see me in the mornings when i'm waking up.

>> reporter: what would they see? >> every night i miss my husband. and i -- i miss laying next to him and kissing him good night. >> reporter: and for tiffany hartley, those are the kinds of memories that will last. far beyond the questions and speculation that have followed her since that fateful day on falcon lake. >> i want my "why" to be answered, and i know i'm never going to know why until the day i can ask god. -- captions by vitac -- www.vitac.com

>> the following is a cnn special report. ♪ >> tonight, aaron hernandez. he was a rising nfl star racing toward greatness. >> what's the meaning on your forearm? >> if it is to be, it's up to me. basically saying my life is in mai hands, and whatever i want my life to be, it's up to me to make it out that way. >> the question now, what sort of life did the ex-patriot make for himself? >> he wanted to be the best. >> but he's accused of the worst. >> how do you plead? >> not guilty. >> why would a football player, a highly successful, affluent, popular football player be a murderer? >> as the nfl struggles to deal with issues of abuse and