♪ this is "nightline." tonight, killer on the loose. a small indiana town shocked by the murder of two teen girls. >> this horrible crime has torn a whole in our families that will never heal. >> a possible suspect's image and voice caught on camera in the victims' final moments. >> down the hill. >> reporter: and 400 miles away, an eerie coincidence. >> everything just started coming back to me. >> could two double homicides have been carried out by the same man? plus, pandora rocks. james cameron guiding us through the new avatar theme park. >> that's when you know you're in an alien world. >> where you can fly on the back of a banshee, and eat and drink like an alien.

some of the park's hidden treasures make a cameo. big screen secrets. ♪ i love it when you call me big papa ♪ >> the notorious big, it's been 20 years since he was gunned down. now his car, the incredible price tag, the lucky owner who bought it by accident. but first the "nightline" 5.

♪ ♪ good evening, thank you for joining us. tonight the grieving grandfather of one of the two teenage girls murdered in a small indiana community. pleading with the public to help bring her killer to justice. police have been circulating an image and voice recording of the potential suspect. captured on one of the victim's phones, just before her murder. here's abc's alex perez. >> she loved taking pictures of anything and everything. >> reporter: these woods of delphi, indiana, now a crime scene. >> we're a small, close-knit community, so this hits very hard. >> reporter: this community still on edge after the horrific murder of two young teens. >> i think it's terrible. it makes me sick to my stomach. >> it made me sick going to the

bridge, thinking, one of my friends died down there. >> reporter: investigators piecing together the last moments of the two girls. >> this horrible crime has torn a hole in our families that will never heal. >> reporter: friends and family shattered by the sudden loss. >> down the hill. >> reporter: tonight, a killer still at large. this voice and photograph, possible clues. authorities say, recorded on the victim's phone that fateful february day. it's around 1:00 p.m. on monday, february 13th. a family member drops the girls off for a hike. authorities believe the girls walked through this nature trail and about an hour after they started their hike, they ended up right here on this railroad bridge. at 2:07 p.m., they upload this photo of abigail walking across the train tracks over this bridge. that would be their last communication. less than an hour later, the teens are scheduled to be picked

up, but they never show. >> they started looking for them, around 5:00. got law enforcement involved. >> reporter: hundreds of volunteers involved, police checking snapchat pictures for clues. liberty's grandfather speaking. >> missing, abducted, we don't know for sure. cell phone has been pinging around town. >> describe that search, the volunteers, this is something that really impacted the community. >> it did, it did. we had, estimating, well over 200 to 300 volunteers. then of course the emergency responders, which included law enforcement, local firefighters. we searched well into the night and the early morning hours. >> reporter: but the next day, detectives discover their bodies, three-quarters of a mile from that very bridge seen in liberty's last snapchat. >> this is rural indiana. most of the people that are born and raised here stay here. it is very uncommon for that to

happen in a small community. it's not something that you get here. >> reporter: a community heart-broken. >> now to think something could have happened here in our own town, it's scary. >> i think everybody is just ready to know what happened and why and who did this. >> reporter: two families, reeling. >> it's the small things that seem to hurt the most. it's just natural to holler for them to come to dinner, or in the mornings to get up and get ready for school. then, expect them to come through the door after school. the silence, when we don't hear their voice. >> reporter: officers combing through thousands of tips. authorities not revealing information about how the teens died, but releasing this chilling audio they believe to be the killer. >> down the hill. down the hill. >> we think there's enough there that somebody would recognize that voice, and we want that person to call us. >> it's always easier to crack a case earlier, witnesses are fresh, you're getting tips early

on and you hope the person might still be in the area. >> reporter: investigators hunting for this man who they call a suspect. >> down the hill. >> reporter: authorities revealing this audio and image came in liberty's phone in her last moments, managing to hit record. >> she's a hero, she had the presence of mind, she didn't feel comfortable and turned on her video camera. >> hope that those will lead to a tip and then an arrest. >> as poor as this picture is, somebody knows. if you're watching, we'll find you. >> reporter: the public has the potential to be the best ally in this investigation. do you know that guy? do you recognize the voice? do you know someone who looked like him, who was in the area? anything they can get is helpful. >> this morning, liberty german's grandfather, appealing to the public for help. >> however small it may seem, it is extremely vital to capture every tip we can get.

please, we need your help. >> reporter: as mystery still clouds delphi, indiana, 400 miles away, a father in iowa hoping this case could help lead to answers in his own daughter and niece's abduction and murder. >> everything just started coming back to me, thinking about what the parents are and the family are going through. and just what i had gone through, and my family's gone through. all those things just come back to you when you see one of these cases. >> reporter: on july 13th, 2012, 8-year-old elizabeth collins and her 10-year-old cousin lyric cook, went for an afternoon bike ride and never returned. >> the last five days have seemed eternal. >> yeah, just like forever. every day is like, we're like, when is it going to end? you know. when is it going to end? when is this nightmare going to end? >> reporter: their bicycles were recovered on this trail next to a small lake after they were reported missing. >> whoever is out there, we're just begging you to bring our

girls back home. >> reporter: the bodies of those two girls were found five months later. elizabeth's father points out the eerie similarities with libthe other murders. both crimes committed on the 13th of the month. >> two kids at once is a very uncommon thing to have happen. and also just being on the 13th of the month, just kinda struck me as really odd. >> reporter: the authorities hunting liberty and abigail's killers telling abc news they've compared notes with investigators in iowa. >> at this point, we're not comfortable saying, yes, there is a connection, or no, there's not. we just don't have enough information. >> reporter: on the surface, these cases have similarities, underage kids, on trails, remote areas of two different states, killed during daylight hours. once you get beyond that, the cases really aren't similar. you have an abduction in the one in iowa, and you also have a

number of states in between these two crime scenes. and so the idea that it's the same guy, i think, is not likely. >> reporter: still as communities grieve in two separate states, the family is holding on to hope for answers. >> one of the biggest advantages of talking about this iowa case now, publicly, is that when cases get publicized, people do come forward. >> reporter: tributes scene across delphi over the last month, for these bright girls taken too soon, as a community waits anxiously for an arrest. for "nightline," i'm alex perez in delphi, indiana. next, it's not a small world. it's another world. behind the scenes of the new addition to disney's animal kingdom. based on avatar's planet pandora.

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♪ with when the movie avatar first debuted in theaters, there were reports of fans exhibiting depression over their inability to visit the planet. now seven years later, there's a cure for the avatar blues. here's abc's paula faris. >> you are not in kansas anymore. you are on pandora. >> reporter: the other worldly landf pandora. from the sci-fi blockbuster "artar" is now becoming a reality. this newest expansion to disney's animal kingdom, pandora, doesn't open to the

public until may 27th. >> you can see the mountains. >> the floating mountains. that's spectacular. >> you can go right under that one central floating mountain there and feel its mass above you. that's when you really know you're on an alien world. >> reporter: but we got an early look from avatar's creator james cameron. >> this is all of the rainforest of pandora all around us now. >> reporter: like the film, this park is his brain child. did you ever think this was going to be possible? >> no. i think i knew it knew it be an amazing world. but i was thinking movie. you can walk around and smell it and touch it. i wander around with a sense of wonder. >> how excited are you? >> very. after titanic and avatar, i can do anything, paint my toe nails by the pool or get a yacht and sail around the world. i like working. in the same way that i work with my design artists on the films, i had an working with the imagine earring

artists. >> reporter: the match with disney was a natural one. >> animal kingdom was founded on this idea that we're going to be fascinated by and be curious about nature, and we're going to have this conservation or stewardship role. when you see the amazing animals in the rest of animal kingdom, it really just reminds you how amazing our own world is, earth. so pandora nested within animal kingdom, i think, was genius. >> reporter: creating this world has been a true team effort. how did you guys do this? >> we're never going to tell you. >> reporter: imagine working for years to make a world created by cgi. >> oh, my, god. >> reporter: into something concrete. >> we're heading into this ceremonial forest. >> reporter: i got a tour of the navi river journey. >> they're called a viper wall.

comparable to a coyote. >> reporter: how do they feel about us invading their world? >> we've been welcomed in to the culture because of our motives. we're here to learn, we're here to educate ourselves. we're here to become better stewards of our planet. >> reporter: that's right. any animosity between the humans and navi in avatar has now faded away, because the park is set generations after the film takes place, when peace prevails. >> the world in which the navi live is in order because they care about it, they care for it. it's not enough to care about the world. you have to care for it. you have to do things, take action. >> reporter: that environmental message was one of the driving forces behind cameron's decision to make the film. when you first tried to sell this socially conscious message to the studio, i would imagine it had to be a tough sell, but why was that message really important to you?

>> because i think we're at a point in human history where we haven't been able to dominate nature until now, nature used to take care of us, now we have to take care of nature. so the child has become the parent in a way. >> reporter: what was seen as a risk for the studio, paid off. avatar becoming the highest grossing film of all time. >> i just recently completed the script for movie five. so we know where the whole story is going across these sequel films. a and we're pretty excited to be embarking on that journey. i've got my cast. >> reporter: do you? >> i've got my key principals. >> reporter: is there any foreshadowing that we'll see? >> maybe some things. you'll say, i saw that at pandora and now i'm seeing in avatar 2, or avatar 3. >> reporter: the release dates haven't been announced. in addition to the sights, pandora has its own cuisine.

>> so these are your creations? >> yes, this is a navi blueberry cheesecake. >> what about the gloing drinks? >> totally fun. what you see here is basically the nectar of pongo pongo and on top, beautiful passion fruit. >> well done. >> reporter: but for those craving a more immersive experience. >> you cannot wait! >> reporter: the flight of passage ride allows visitors to take a heart of had pounding ride on a banshee. >> and this is where people will be able to link with a banshee and actually fly across pandora. >> reporter: the film's co-producer was my personal guide. >> i'm doing my best mr. roboto. this is all going to match me to my own personal avatar? >> that's right. we'll sync you up, find your match and get you flying. so these are the link chairs that will connect us to the banshees and let us fly across pandora. put on your riding goggles.

>> all right, it's go time, but you can't watch, because it's still top secret. we can't show you yet, but take my word for it, the ride is even more exhilarating than those epic movie scenes. by night, pandora has yet another dazzling surprise in store as the sun sets, the world is awash in a bioluminescent glow. you say it's a trance formative adventure. has it transformed you in some ways? >> it's transformed my perception of what is possible in the real world. if you had asked me, i would have said this is not possible, what they've created here. >> reporter: for "nightline," i'm paula faris in orlando. ♪ and next, how one lucky woman stumbled into a fortune. now about to sell the car that the notorious b.i.g. was shot in. but a warning from biggie. mo money, mo problems. ♪ i'm coming ♪ b. i g., po, ppa.

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♪ ♪ and finally tonight, we remember one of rap's biggest legends on the 20th anniversary of his death. >> reporter: a beat-up '97 suburban, 111,000 miles on the clock. yours for $1.5 million. because it's the most notorious suv in rap history. 20 years ago to the day, the notorious b.i.g. shot dead in this vehicle. a drive-by in l.a. >> police investigate the deadly wilshire boulevard ambush of notorious b.i.g. >> reporter: big papa, already arguably the most influential rapper of all time. ♪ ♪ throw your hands in the air ♪ if you're a true player >> reporter: today diddy posted this. >> he's fed a lot of families, made a lot of people dance, made a lot of people feel good. >> reporter: the current owner of the suv had no idea when she

bought it. >> we t t t t t t t unusual that there was a hole in the seat belt. we had the car for a few years and we got a phone call. >> the l.a. police department is holding on to the original doors. they'll be returned to her if and when the investigation is ever concluded. >> reporter: biggie, a victim of that early '90s east coast/west coast hip-hop rivalry fueled by the likes of -- ♪ ♪ >> reporter: right now, memento merchants moment in time is also selling the bmw in which tupac was shot dead in vegas the year before biggie. also $1.5 million. both murders still unsolved, and yes, we've been listening to faith and puff daddy's lament that long. ♪ ♪ i'll be missing you >> reporter: by the way, kelley blue book value on biggie's death car.

>> the owner and i have been offered over a million dollars for it. but we're holding out for the full $1.5 million. >> reporter: in the words of biggie. >> the more money you make, the more problems you get. >> reporter: i'm nick watt in los angeles for "nightline." ♪ ♪ >> thank you for watching abc news, and as always we're online at abc news.com and our "nightline" facebook page. thanks for the company, america. goodnight.

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