Tonight, what so many teenagers are doing right now, across the country, having parties, some of them with alcohol, drugs and in our first story, something else, revenge against controlling parents,... See More
Tonight, what so many teenagers are doing right now, across the country, having parties, some of them with alcohol, drugs and in our first story, something else, revenge against controlling parents, for teenager Tyler Hadley, the party to end all parties began with these ominous words, when someone asked, when will your parents come home? He said, they won't, trust me. Here's Ryan smith. Reporter: Nestled on Florida's treasure coast, 40 miles north of west palm beach, sits Port St. Lucie -- a city once designed for retirees, now teeming with working families. It's a maze of streets that all kind of wind together. Reporter: There's the sense on these empty streets that something's amiss -- even the street signs aren't quite right. They didn't have time to spell the street names correctly. Reporter: Growing up here is a modest sort of happiness for any kid. But as novelist, Nathaniel rich learned, that gets old. Every teenager complained about how boring it was in port St. Lucie. "The only thing to do is drink and get high. Have parties." Reporter: And it's a party that happened here that no one will ever forget. You're looking live at the Port St. Lucie home where police say a 17-year-old boy killed his parents. A drug-addicted teenager who just wanted to party. He threw a big party at his house only two people didn't show up -- mom and dad. They couldn't come. They were locked in the bedroom -- dead. The million-dollar question is, why? Reporter: A 17-year-old killing his parents -- an event that left a confused community looking to its teenagers for answers about high school senior Tyler Hadley. His parents were getting, you know, tired of him going out late, and getting drunk. They got more strict. His mom took his phone away. He was upset and he said he hated them. Just something like teenagers say. Definitely something that really upset him. Everybody has, like, sick jokes. So we just thought it was like a sick joke. Reporter: But what turns a teenager's sick joke into a sickening reality? Tonight, we go inside the investigation into what made a boy scout turn into a teenager who did the unthinkable. Mike Mandell has known Tyler since they were both 8 years old. He lived just a block away. So, you know, his parents. Reporter: What were they like? They seemed like great parents to me. Reporter: And how did Tyler feel about his parents? Blake and Mary Jo Hadley thought sunny Port St. Lucie was the perfect place to raise their two boys, Ryan and Tyler. Mary Jo was a schoolteacher. And she loved kids so much. She dedicated her life to her two -- two boys. Reporter: Their father Blake loved his job at a local power plant, but his passion was his sons. The baby, Tyler, and Ryan, six years older. What was Blake like with the boys? He had a ball with 'em. He loved 'em. Reporter: And in the beginning Tyler seemed to be a happy little boy, celebrating birthdays and holidays with his family. He was constantly hugging his mom -- I mean, constantly. He would stand behind her and hug her and, you know, he was -- he was an affectionate kid. I remember him being a funny kid. He had a quick sense of humor. You never knew what was going to come out of his mouth. Reporter: In a good way? Sometimes. Reporter: It was a quality that drew Mike to Tyler. I was just walking around, trying to find a friend and stumbled upon Tyler. He slowly became my best friend. Reporter: Over time Tyler began opening up -- sharing with Mike his secrets and his insecurities. He a lot of times bashed himself, and said he wasn't good enough. He just always thought someone was better than him. Reporter: But what started as a kid's self-doubt turned into a teenager's anger. He started skipping school, hanging out with the wrong crowd, getting on drugs. You know, that's just things he was starting to do, was getting in trouble. He was starting to steal. And they said, "Just hide your purse." I just thought it was one of those teenage things. Reporter: Tyler's parents started cracking down. How did they discipline him? They really did everything possible. As far as taking away the cell phone. Bits and pieces of freedom that children really, you know, cherish at that age. Reporter: But Tyler pushed back, continuing to defy his parents. He didn't like following any rules. He liked going out, doing drugs. Then his parents caught on, he was already comfortable living that way, and he didn't want anyone to change it. Reporter: Nancy grace has followed the case. They wereeginning to discipline him more and more and by that I don't mean take him out to the woodshed and give him a spanking. They would take away privileges. Well, Hadley would have none of that. His frustration and anger mounted. Reporter: By the time Tyler was 17, his parents were at their wits' end. They put him into an outpatient substance abuse program, but nothing changed. He came home drunk one night, and he crawled through his window, and his parents woke up. And they took away his phone and his car. He felt that she was over disciplining him. And, he said he wanted to kill her. Reporter: Did it sound like he might actually do it? Absolutely not. Reporter: And Tyler's parents were keeping a closer eye on him, taking him to a family reunion in Georgia -- just one week before life would change forever. We really enjoyed having him. He was very polite, I mean he was -- I never saw Tyler lose his temper, ever. That's what is so bizarre about everything. Reporter: Posing for family pictures one minute, but plotting with friends back home the next. He was texting his friends and telling them, "We're gonna have a party when I get home." So he was planning it while he was up there. Reporter: And three days, this first ominous Facebook post -- "Party at my crib tonight -- maybe." Tyler said he was gonna have a party tonight. A friend facebooked him "What about your parents? Are they gonna come home in the middle of the party?" And Hadley writes back "They won't, trust me." Reporter: A party at Tyler's house seemed odd with his parents now tightening the reins -- but it was something else he said that really got Mike's attention. He tells you something about what he did the night before. Yeah, he said he was contemplating murdering them that night, while they were sleeping in their bed. And he just didn't -- he said he couldn't do it. He didn't have it in him. Reporter: And what did you think when he told you that? I got a weird feeling in my stomach, but -- it's Tyler. There's no way he would do this. Reporter: Then -- a few hours later. A second Facebook post -- "Party at my house, hit me up." This time there was no "Maybe." Tyler Hadley's house party was set. He was bragging about it for days, he was going to have the party come hell or high water and nothing and nobody was going to get in his way. One of my friends had gone on Facebook and seen the post about the party. There was so little to do in Port St. Lucie to do that night. Any teenager who heard about the party was, was going to check it out. Reporter: Around 9:30 P.M., Tyler picks up Mike and some other friends and they head back to his house. Jesse Duryea is in the car. When we were Pullin' up to And then he said, "Something real crazy's gonna come out in the next week." Said, "What do you mean?" And he said, "You'll find out." Asked him where his parents were, told me they were in Georgia. There were parents there. It was a free-for-all. Kids could smoke inside the house. They were drinking. Kids were bringing beer and, and pot and pills. Reporter: What's it's like inside? Young people drinking and sitting around talking. But, the weird thing was, most people in there, Tyler didn't even know. I didn't know 'em. I don't know them. They were strangers. Reporter: You think he wanted to be known as having this huge party? Maybe. That's the only thing that makes sense. Reporter: As the rowdy party rages on, a neighbor across the street makes a noise complaint. I woke up to, you know, squealing tires and kids hanging out of the car yelling. So, I did call 911. Reporter: Officers respond, but with no immediate cause for alarm, they leave the teens with
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