Tonight we begin with the shocking crime that landed two Virginia tech students behind bars. Accused of kidnapping and murdering a 13-year-old girl. Now we're learning new details about how they... See More
Tonight we begin with the shocking crime that landed two Virginia tech students behind bars. Accused of kidnapping and murdering a 13-year-old girl. Now we're learning new details about how they allegedly planned their horrifying step by step plot to end the girl's life with chilling detachment. ABC's Eva pilgrim takes us inside the case. I never had one of my friends die. Reporter: She was the sweet Virginia middle schooler found murdered. Tonight the details of Nicole lovell's short life and gruesome death coming into focus along with new concerns about the dangers of social media. She seems like she was a nice girl. Any understanding of why they behalf made fun of her? Just from her scars. Just because it's middle school. Reporter: Nicole faced terrible medical problems as a child. At the age of 10 months old, coli received a liver transplant and fought for her life. Reporter: The scars were fading, she was older, making connections on social media. That's why she started going to Facebook. Someone to give her attention, make her feel loved. Reporter: Making that awkward transition from childhood to young adulthood and her friend says she was meeting men online. I found out she was dating a guy that was over the age of 18. You could tell he was way too old. Reporter: Shortly after, she says, another mysterious januaman. January 27th, Nicole climbed out her bedroom window carrying only her phone and a minion blanket. I have had it to right here with people suggesting that this little girl is somehow responsible for all of this. What does she know about flirtation and dating and sex? The girl was lured out holding on, clutching on to her binky, her minion blanket. Reporter: The police say she snuck away to meet this man and why wouldn't she have trusted him? David Eisenhower was a track star, good-looking, successful. I realize in the moment that I am doing things that other people wish they could be doing. Reporter: He'd been on television. Yet I still have goals for myself because there are people who are better than me. And I will personally not stop until I reach my peak performance. Reporter: Nicole never came back. Soon almost 1,000 volunteers were searching and authorities scoured for leads until they were able to track the last messages from Nicole's phone leading them to Eisenhower. The investigation led us to 18-year-old David E. Eisenhower, a Virginia tech student. Reporter: With Eisenhower in custody authorities soon locate Nicole's body, 80 miles away in North Carolina. It's about two miles from a home owned by his extended family. I'm sure that it's something Nicole's family would like to know, why did she have to end up here, left in this condition, discarded in the manner she was? Reporter: The investigation leading authorities to identify and arrest what they say is an accomplice, a friend and another student from Virginia tech, Natalie keepers, charged with helping Eisenhower dispose of the body in these woods. I'm assuming that it was probably done after dark and they may have thought they were further away from the road than they actually are. Because there's no lighting out here. Reporter: Prosecutors allege keepers also helped Eisenhower plan the gruesome murder, plotting for weeks, they say scouting locations, and even buying tools. When police showed up to talk to keepers, prosecutors say she immediately tried to warn Eisenhower, texting him "Police." It was then she allegedly told FBI investigators Eisenhower killed noik ankle and put her body in his Lexus, keepers allegedly saying she was excited to be a part of something secretive and special. That's really a stunning comment. There is a great deal of callousness about that. She and Eisenhower discussed how the murder would be committed, cutting this little girl's throat, as though they're talking about an object. Reporter: Retired FBI profiler Dr. Mary Ellen o'toole saying this is a complicated case with multiple motives spelling disaster. There's synergy that came together that made this a very lethal pair. A very preliminary determination of the cause of death is stabbing. Reporter: For Nicole's mother, it's too much to bear. Her favorite color was blue. Nicole was a very loveable person. Nicole touched many people throughout her short life. I can't do that part. Reporter: While authorities wait for the results of an autopsy they have concluded that Nicole was using a messaging app called kick to communicate with Eisenhower, raising questions about possibly dangerous encounters. I'm willing to say kick is a devil for young children. It's like a free ability to text. Anything you want. Parents can't see the phone Numbers that are coming in and out. Reporter: Experts say many of these anonymous apps are popular with teens and predators. You can sign up as anybody you want to be. It really becomes a private hunting preserve for some of these pedophiles. Reporter: Here's how kik works. Download the app for free, add any name and any photo, send messages, photos, and videos, and you don't even need texting service. Parents sometimes take away these data plans thinking that, well, the child has abused it. But they only need a wi-fi signal to be able to communicate. Reporter: ABC reached out to kik who told us kik cooperated with the FBI for their investigation, kik cooperates with law enforcement to combat child predators anywhere in the world, even upon provision of a court order or emergency situations like this one. Sorted by geographic location, by school, by age. How do you keep your family safe? The first thing parents need to do is set ground rules. Secondly, know the technology, know how the parental controls work. Third, they need to talk to their kids, have ongoing conversations about safety, so that kid when it comes time makes that safe and smart decision. Reporter: And it's not just kik. There are many other apps kids can use to hide things from their parents. Blogger Liz gambener showed David Wright how easy it is to hide incriminating photos. When you open it up and I type in my password and hit the percentage sign it's a hidden photo album. Reporter: Sending photos as easy as point and click. Kid swap the files in apps such as snapchat, kik, yik yak, his per, making sharing large Numbers of files fast and easy. Kids will always be savvier than mom and dad, one step ahead of us, that's the nature of the game. Reporter: Nicole's friend Carrie said she tried to tell an adult months ago after she noticed Nicole was communicating with an older man. I went to the officer at my school. And wrote down his name on a piece of paper and handed it to him. Reporter: The blacksburg police department denying she alerted the officer about Eisenhower saying, had a student or even Nicole herself reached out to him in advance of her disappearance about anything that could cause concern, he would have act the on it through the appropriate channelschannels. Did you make this up? No. I think if he would have done something he could have seen the guys on her Facebook and he could have stopped all of this. Reporter: Nicole's family filing into court wearing blue ribbons hour before her burial, mourning a daughter gone too soon. A preliminary hearing for Eisenhower has been scheduled for March 28th.
This transcript has been automatically generated and may not be 100% accurate.