tonight on "nightline." >> oh my god! >> the deadly school rampage. new images of the gunman targeting classrooms again and again. >> very focused on what he was doing. >> students reporting the horror. s.w.a.t. teams rescuing teens who thought they were doomed. >> everyone out the door! >> i just said, mom, i love you so much, i think i'm going to die. >> escaping a landscape of brutality. >> i saw them on the ground after they were shot. there was blood everywhere. >> now the latest in the investigation. how police found the suspect. >> i thought, could this be the person? is this who i need to stop? >> details of his expulsion. stories of animal cruelty and obsession with weapons. >> aggressive, crazy, weird, psycho. >> and the victims ripped from their families. a community in mourning.

and the acts of bravery and self sacrifice in that school that saved untold lives. this special edition of "nightline," "deadly school rampage," will be right back. hey hun. look at all this extra room i have on this king size ikea bed. are you wearing a... duvet cover? why yes. yes i am. where's mom? we finally redid our bedroom and she's prettttttttttty into it. what's your dream? at ikea, we help you live it. make the dream yours. ♪ ♪

there are two types of people in the world. those who fear the future... and those who embrace it. the future is for the unafraid. ♪ ♪ hey hun. look at all this extra room i have on this king size ikea bed. are you wearing a... duvet cover? why yes. yes i am. where's mom? we finally redid our bedroom and she's prettttttttttty into it. what's your dream? at ikea, we help you live it. make the dream yours. ♪ . good evening.

new diagram tick details emerging from inside the florida high school shooting that shattered so many lives. the students who were trapped in the nightmare telling abc's david muir their harrowing stories. >> i wasn't able to sleep. i saw his face in my head and shots, hearing it. >> reporter: for the survivors of the parkland shooting, the moments many feared would be their last replaying over and over in their minds. >> never think it will happen to you. to your school. until it really does. and it just doesn't feel real. >> reporter: junior mckenzie hill was with her twin sister moments before the shooting began. >> i was in the restroom, i heard 10 to 15 gunshots. i go to the stall really quick, i grab two people near me, tell them we need to get to class right away. >> you're in the bathroom on the second floor, you hear the gunfire. your twin sister is downstairs? >> in the classroom i was in. >> reporter: she saw the shooter down the hall heading down the stairs. >> and that's the moment i panicked. the girl with me was hyperventilating because she had asthma. we get in the classroom, we were just sitting down, i had contact

with my sister. then -- she told me she loved, and i heard the gunshots, and she didn't answer me. >> reporter: mckenzie describes heart wrenching moments separated from her twin. >> we heard screaming and crying. then we got silent because all the kids who were shot in the rooms over, i guess they lost so much blood, and we heard no gun shots for 10 minutes. 40 minutes later i still received no messages from my sister. >> reporter: downstairs in that classroom on the first floor, junior jonathan blank. >> there's a glass panel on our door. and it's like a rectangular glass window. he open fired from inside the hallway through the door and just started spraying through the door. >> reporter: in this chilling video -- >> oh my god! >> reporter: the deafening shots ringing out. you could actually see jonathan. he was on the floor along with so many of his friends. you can see his sneakers right

there. >> i was laying down. four kids in my class, they got shot. two of them, i believe, passed away. i saw them on the ground after they were shot. there was blood everywhere. and it was just horrible. >> reporter: the seconds turning into minutes. it seemed an eternity. >> finally the cops, we hear them screaming. we had to put our hands up. they came in with assault rifles. pointing them to make sure that no one -- the shooter wasn't in our class. and as i was making the right turn out of the class, i saw two kids laying in the middle of the hallway, dead. just dead. >> reporter: a sight no high schooler should have to see. how terrifying was the whole thing? >> it was the most scariest moment of my life. i've never experienced anything like that. >> reporter: jaden bear, a junior, fled to a closet where she hid for hours with other students. in what she thought were her last moments she texted her mom.

>> mom, i love you so much, i think i'm going to die. >> reporter: her teacher trying to keep everyone hiding in that closet calm. >> i knew that she wanted to be emotional, but she couldn't, for us. because if she was, then so many other people would have broke down. >> reporter: the students are evacuated out of the school and told not to look around, to keep their hands in the air. >> i was looking around to see everything that was going on, i saw security guards down on the ground. i saw people, blood everywhere. i just like couldn't take it all in. then i get out of the school and i saw my sister. >> what was that like? >> it was the best feeling. if she would have died -- i don't know what i would have done. >> reporter: but for too many parents, there is only grief tonight. on that fateful valentine's day sending their children off to school not knowing that they would never come home. how many of you know someone who did not get out alive? >> we had a friend, me and my group of friends, that we

haven't heard from. and not until like 2:00 a.m. last night that it was confirmed. >> i lost someone very close to me that i saw as a little brother. and that hurts. nobody should -- nobody should have to deal with that today. nobody. nobody deserves that. >> reporter: they then show us the photos of the friends they have lost. >> this is my classmate nick. he was actually going to -- he was on the national team for swimming. he committed to the university of indianapolis. a couple -- like two weeks before this happened. great classmate, great person. always so nice. >> reporter: they were teenagers filled with promise. dedicated coaches and teachers too. >> we had an athletic director, campus monitor, who responded immediately. unfortunately, those two heroes gave their lives for our kids.

>> when you finally do get back to school, how many of you have teachers you want to thank? yeah. the whole group. >> every teacher deserves to know that they're a hero. they're a hero. >> reporter: the stories of remarkable courage already emerging. there was the beloved assistant football coach, aaron feis, a graduate of the school who came back to his alma mater to work with young athletes. >> he was one of the greatest people i knew. a phenomenal man. >> reporter: witnesses say he responded to the initial call after hearing the sounds of gunfire erupt. >> i'm close with mr. feis. so he kept waving at me to leave. then i saw the shooter run after mr. feis. and i saw mr. feis get shot. >> when aaron feis died, when he was killed, tragically, inhumanely, he did it protecting others, you can guarantee that, that's who aaron feis was. >> reporter: the weight of survival a heavy burden for these teenagers. i know a lot of you have seen grief counselors. how many of you got help today?

almost the entire group. these students feeling blessed to be alive. now trying to send a message to the nation. to help them keep this from happening ever again. what do you all want to hear from the people who we elect to solve these problems? what do you want to hear from them? >> gun control. >> how are they going to stop this from happening? it's obviously happened way too often. it's a recurring trend. >> probably that any person should be able to obtain an ak 15. >> i know this is a big wakeup call and i want people to rise up as a community, a nation, and realize we can make this the last time something like this ever happens. >> reporter: for "nightline," i'm david muir in parkland, florida. >> our thanks to david. when we come back, the new recordings from inside the florida high school as the gunman fired intoand stories fr about the suspect's bizarre

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♪ they're super... ...but they can fly. ♪ united. helping superheroes fly. ♪ ♪ there are two types of people in the world. those who fear the future...

and those who embrace it. the future is for the unafraid. ♪ ♪ hiiiiiii! hey hun. look at all this extra room i have on this king size ikea bed. i'm rolling! are you wearing a... duvet cover? why yes. yes i am. looks good, doesn't it? (phone buzzes) you can't see me can you? nope. it's because of these new blackout curtains! hi kids!! where's mom? we finally redid our bedroom and she's prettttttttttty into it. what's your dream? at ikea, we help you live it. make the dream yours.

♪ according analysis by "washington post" more than 150,000 students have experienced a school shooting since columbine in 1999. in new recordings from the florida massacre, painting a portrait of what some of them may have been through. a warping, many of these videos are disturbing. nbc's tom llamas brings us the latest. >> we sat together in spanish class. now she's going to be an empty desk.

>> reporter: liam kiernan lost his best friend yesterday afternoon when the world fell apart at marjory stoneman douglas high school. >> i can't believe that i'm here right now, and why did -- why did i get out and she didn't? and why did this happen? like we could have done so much to stop this. >> holy [ bleep ]! [ bleep ], [ bleep ]! >> reporter: a scene we all hoped we would never see again. >> i was in the classroom. all i hear was shots. and i was just like, oh my gosh, what's happening? >> reporter: it was the last period of the day when the gunman opened fire with his ar-15. [ sobbing ] >> reporter: a school employee immediately calling code red. >> we're in the school, active shooter, it's not a drill, i heard one gunshot. we thought it was a drill initially but it's not. >> the fire alarm got pulled and kids were evacuating. i heard five pops. >> reporter: the suspect, a former douglas high school student, allegedly shot into at least five classrooms on two floors. >> he was just very focused.

he was very focused on what he was doing. >> reporter: terrified students in locked classrooms. >> i couldn't believe something would happen to a school that got voted the safest place the year before. >> reporter: first responders on the scene desperately tried to track down the suspect. >> do they know where the shooter is? >> we don't know but we're heading in the building. >> reporter: eric due val filmed as the police broke the window of a classroom door to gain entry. >> everyone on the floor! >> reporter: in another classroom, screams of anguish from the wounded as police led the rest of the students to safety. >> i thought i was going to die. >> reporter: ten people still in the hospital. 17 are dead. including teachers, students, and coaches. 14-year-old martin duque, a freshman. his brother shared the news on instagram writing, words cannot describe my pain. i love you, brother.

jamie guttenberg, also 14, her father accepting condolences on facebook. i am broken. hold your children tight. gina mourning the loss of her daughter. writing, she was smart, loving, caring, and a strong girl who brightened any room she entered. authorities say the 19-year-old suspect eventually dropped his rifle on the third floor stairwell and exited the school. >> the suspect crossed fields and ran west along with others who were fleeing and tried to mix in with the group that were running away. >> reporter: incredibly, he then went to a nearby walmart, bought a drink, then went to a mcdon d mcdonald's. >> hechd he was at the mcdonald's by the school. >> reporter: around an hour after he opened fire, the suspect was spotted by officer michael leonard. >> he looked like a typical high school student. and for a quick moment, i thought, could this be the person? is this who i need to stop? >> reporter: he was apprehended about two miles from the high

school. >> the fact is, law enforcement responded in a very quick manner to the school and probably established a perimeter to ensure nobody was able to escape. however, the suspect clearly had in his mind he was going to shoot and then try to escape. and he was able to get outside of that perimeter before it was formed and contained around the school. >> reporter: within hours, police say he confessed to the killings, stating he was the gunman who began shooting students. investigators are piecing together the suspect's background. adopted as a baby, he lost his father when he was 5. just last november, he lost his mother to the flu and went to live with a friend's family. the neighborhood where he grew up, big homes with well-manicured lawns. neighbors say it was so normal. the suspect really stood out. >> aggressive. >> reporter: he remembers him having a violent side. >> he cornered squirrels, throwing rocks at it, trying to

kill it. >> reporter: former classmates paint a more twisted picture. they say the suspect was obsessed with guns and was disciplined for bringing bullet casings to school. >> about a year ago, i saw him upset in the morning. and i was like, what's up? he said, i swear to god, i'll shoot up this school. >> reporter: according to abc affiliate the suspect was expelled february 8th last year, three days later he bought the ar-15 at this gun store less than ten miles from the school. >> once the school expelled the suspect, they should have known that he may have had a beef with the school. >> reporter: his social media posts also suggested something might be off. >> in september last year, i received a comment on my youtube channel, i'm going to be a professional school shooter. and thought that to be odd and disturbing. i forwarded that screen shot to the fbi. and reported it to youtube. >> reporter: the fbi says they investigated. >> the fbi also conducted internal database reviews and

open source checks. no additional information was found to positively identify the person who posted this comment. there was no connection found to south florida. >> reporter: tonight the agency saying they couldn't track down who the user was. and they're conducting a review of how that tip was handled. >> if as the fbi said they were not able to determine who that person truly was, my question is, how many people are there out there, in america, who have posted similar type of blogs that indicate that they are inclimbed to commit violence, and they have not been able to determine who those people are? that's a huge problem. >> reporter: sources tell abc news this social media account belongs to the suspect. this photo shows him holding a pistol. in another, holding a large knife. law enforcement sources say these social media pages are being scrutinized for clues. law enforcement sources tell abc news the suspects said voices in his head corredirected him on t attack. >> he's on suicide watch, the

childed deeply troubled. >> reporter: proposed regulations to limit access to guns have brought support like expanding background checks and a ban on gun purchases by people on no-fly lists. this is something we can't let keep happening. if we do and we get used to it, it's going to happen again. this is time for the country to take a look in the mirror and realize there's a serious issue here. >> reporter: president trump addressed the nation today. >> no child, no teacher, should ever be in danger in an american school. >> reporter: but he never mentioned the word "gun" once. instead defining the issue through mental health. >> we are committed to working with state and local leaders to help secure our schools and tackle the difficult issue of mental health. >> reporter: but just weeks after taking office last year, the president blocked an obama-era rule that made it tougher for the mentally ill to obtain guns. mother laurie alhadeff who lost daughter alisa in the shooting

expressed her outrage. >> president trump, you say what can you do? you can stop the guns from getting into the shooters' hands! >> reporter: the type of gun used in this school shooting, the ar-15, it was used in las vegas last year. san bernardino in 2015. and sandy hook in 2012. >> i have hunted all my life. i have had guns all my life. i still hunt with my son. but an ar-15 is not for hunting. it's for killing. >> reporter: in florida, you can purchase an ar-15 at age 18. which is exactly what the suspect did. >> they're technically adults but we really have to take a look at that law and regulation and determine whether an 18 or 19-year-old are really able to handle that kind of weapon safely and are in the position mentally to not go into a school and shoot everybody. >> reporter: there are an estimated 5 million to 10

million ar-15 rifles in the united states. this afternoon the suspect appeared via video conference for his bond hearing. >> i have something very important to tell you. you're charged with some very serious crimes -- >> reporter: facing 17 counts of premeditated murder and held without bond. >> i find probable cause, i further find the proof of guilt to be evident -- >> reporter: tonight as america does after a horrific act of gun violence, the search for answers to, why? will the answers come in time to prevent another horrific shooting? for "nightline," i'm tom llamas in parkland, florida. >> our thanks to tom. and we'll be right back. with the most lobster dishes of the year. new dueling lobster tails has two tails that'll fight to be your favorite. one topped with creamy shrimp and scallops, the other... steamed with lemon and herbs. and no, you're not dreaming, classics like lobster lover's dream are back too, along with decadent new lobster truffle mac & cheese.

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♪ and finally tonight, we take a moment to remember the lives lost in yesterday's massacre. >> as our nation mourns again, debates gun safety and mental

health again, it was nelson mandela who said, it always seems impossible, until it's done. thank you for watching "nightline." as always, we're online on our "nightline" facebook page. thanks for the company, america. good night.

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