Produced by Josh Gelman

This story first aired on April 27. It was updated on October 26.

When the body of 16-year-old Jchandra Brown was found deep in the woods of Payson Canyon, Utah, in 2017, authorities thought the scene initially looked like a clear-cut case of suicide; it was anything but that. There were clues that something wasn't right. Nearby, police found a note.

"It says, 'My name's Jchandra Brown and I hated my life,'" Utah County Sheriff's Detective Quin Fackrell tells CBS News correspondent David Begnaud. "'Watch the video. It's on my phone.'"

Brown's phone, also found nearby, contained a 10-minute video of her suicide that was recorded by someone she knew. They also found two grocery bags, one of which had a receipt for rope purchased with a debit card belonging to Tyerell Przybycien.

As police continued searching the area where Brown was found, Przybycien walked up.

"He introduces himself to me as Tyerell Przybycien," recalls Sgt. Josh Chappell. "And he goes, 'I think you want to talk to me. I need to tell you the whole story.'"

Przybycien told police he was just helping Jchandra do what she wanted to do, but detectives later discovered new evidence that showed this may have been Tyerell's plan all along – such as a text he sent to a friend stating, "It's like getting away with murder." And with that, Utah County prosecutors decided to charge Przybycien with first-degree murder.

"In his mind, I don't think that he was committing murder. He was helping her do what she wanted to do," says Neil Skousen, Przybycien's attorney.

"This goes beyond making bad mistakes," says Prosecutor Chad Grunander. "This was criminal behavior. There's no doubt in my mind that Jchandra does not die on May 5, 2017, if she had never met Tyerell."

"ONE OF THE HAPPIEST KIDS IN THE ROOM"

It's been more than two years since Sgt. Quin Fackrell and Sgt. Josh Chappell of the Utah County Sheriff's Office were called up to Maple Lake in Payson Canyon -- about 20 miles south of Provo, Utah.

Det. Quin Fackrell: We cover the areas that people go to get away from people. Those are our areas.

It's a popular location with snowmobilers and back country skiers in the winter and hikers and hunters in the warmer months. Unfortunately, this remote area attracts people for other reasons as well.

Sgt. Josh Chappell: We get a lot of people that like to go to the mountains or to the areas outside of the city and cause harm to themselves. … So, we see a fair amount of suicides that we investigate.

One of those investigations was the suicide of 16-year-old Jchandra Brown, which occurred on May 5, 2017.

Sue Davis says her daughter's vibrant blue hair matched her super vibrant personality Dustin Lewis

Sue Bryan relishes the visits that she has with her son Dustin and her grandchildren. But missing from the family is Bryan's daughter Jchandra.

David Begnaud: Tell me about the blue color in your hair.

Sue Bryan: It's in honor of my daughter, 'cause she loved having her vibrant blue hair which matched her super vibrant and bubbly personality.

Sue Bryan: Her nickname was when she was little was Jelly Bean. Jelly Beanies.

David Begnaud: Did you call her Jelly or Jchandra?

Sue Bryan: I called her both.

As a young girl growing up in Twin Falls, Idaho, Bryan says Jchandra always seemed to be one of the happiest kids in the room.

Sue Bryan: If you met Jchandra, you just fell in love with her instantly. … She was very active and adventurous. … and she wanted to try and do anything. … So she would do the water slides … She was in volleyball. … We went picnicking, dancing. She loved skiing and tubing. … She was a cheerleader. … She won so many awards, she was so good.

In 2016, Jchandra's mother and stepfather moved her from Idaho to Spanish Fork, Utah. They wanted to be closer to Jchandra's brother Dustin and his family.

David Begnaud: How'd she get along with the kids?

Dustin Lewis: Great. I mean they adored her. … "Jchandra, Jchandra's coming?" Oh, just super excited.

With the move to a new town came a new school and, of course, new friends.

Hannah Baldt: Me, Grace and Jelly usually called ourselves the Three Musketeers.

Though they didn't know Jchandra very long, Hannah Baldt, Grace Jackson and Ashton Wall say they were lucky to have known her at all.

Hannah Baldt: She connected to me in a lot of ways that other people didn't. She –

David Begnaud: She got you.

Hannah Baldt: She, she got me. … I've never met anybody like her.

Grace Jackson: There was never a dull moment or boring moment when I was with her. We always found something to do. We always had fun doing it.

Ashton Wall: She was always hopping around the place. … she was like jelly holding everyone together, you know, PB and J.

Hannah Baldt: She was outta this world, she really was.

But after living in Utah for just a few months, Jchandra seemed to need someone to hold her together.

Sue Bryan: I got the sense she was sad and having problems … she just wasn't herself.

David Begnaud: What was different?

Sue Bryan: She wasn't happy all the time. And she was frustrated very easily. She wasn't feeling good. … And I actually took her to a doctor.

Jchandra was prescribed an antidepressant. She had been treated for depression a year earlier back in Idaho.

Dr. Harold Koplewicz: Depression really affects the way you think. It affects the way you behave. It affects the way you experience the world.

Dr. Harold Koplewicz is one of the leading innovators in the field of child and adolescent psychiatry and the founder of the Child Mind Institute. He never treated Jchandra, but "48 Hours" asked him to take a look at her case.

Dr. Harold Koplewicz: I think that what all young adults … struggle with is impulse control and the intensity of their feelings. … They freeze or they're boiling or they hate you or they love you.

David Begnaud: Zero to 60 quickly.

Dr. Harold Koplewicz: Right.

David Begnaud: Did you talk about that depression with her?

Grace Jackson: All the time.

Hannah Baldt: All the time.

Sue Bryan: I think in my heart what depressed Jchandra was not being close to her friends and family in Idaho.

David Begnaud: Did she ever talk about life in Idaho -- missing it?

Grace Jackson: Yes.

Hannah Baldt: Yeah.

David Begnaud: She did.

Grace Jackson: All the time. All of her memories are from Idaho.

Dr. Harold Koplewicz: I think the move from Idaho to Utah was much more problematic for her than we would expect.

David Begnaud: Was there ever an indication that Jchandra might harm herself?

Grace Jackson: I know that she self-harmed.

David Begnaud: By doing what?

Grace Jackson: Cutting.

Dr. Harold Koplewicz: Cutting has become much more frequent than it was 20 years ago. And so, very often when you do talk to cutters, they will tell you, "I feel nothing. And when I cut I feel something." But that's a sign of depression. That's a sign of someone's really reaching out for help.

Symptoms, treatment of teen depression

And then came the events of May 5, 2017, which turned out to be the last day of Jchandra's life.

David Begnaud: She got in trouble for smoking pot?

Sue Bryan: Having it, not smoking it. Getting caught with it.

And this wasn't the first time she got caught. It happened once before, in Idaho. This time, though, she got suspended from school.

Ashton Wall: She was so worried and freaking out about, you know, what her mom would do because she was so … upset that … her mom might be mad at her.

Dr. Harold Koplewicz: She's shamed and she feels hopeless. … "And now I'm caught with weed." So these seemingly insignificant events for someone who's very vulnerable can mean something.

Sue Bryan: She came home from school that day … and she goes. "Alright, aren't you going to yell at me?" … And I said, "No, I'm not. … I figure you've been in trouble enough at school that there's no reason for me to yell. And we can talk about it when we're calm." And I said, "If you have homework, you better get it done because … you have work."

Jchandra's punishment? Bryan confiscated her cell phone. Later that afternoon, she drove Jchandra to her night job at a nearby Wendy's.

Sue Bryan [emotional]: And that was the last I seen her. … I don't know if she thought … that I was mad at her or that I didn't love her. I don't know, 'cause I didn't get to talk to her again.

David Begnaud: What time was she supposed to come home?

Sue Bryan: So she was supposed to get off around 1:30.

David Begnaud: In the morning.

Sue Bryan: Yeah.

But Jchandra never made it home.

Sue Bryan: And it's kind of weird. … I sat straight up in bed and said, "Jchandra." And I freaked out. … And I can't call her because I took her phone away.

David Begnaud: Oh, right.

Sue Bryan: And, so, I called the police. … And I told them that I guess my daughter had run away. … And, so, they put a report out and they went looking for her.

The police didn't find Jchandra that morning, but someone else did.

FINDING JCHANDRA

Getting "48 Hours" up to the spot where Jchandra Brown's body was discovered was not an easy task. It took two search and rescue vehicles, three pairs of snowshoes and some pretty careful trekking in the March snow. But we wanted to show just how far Jchandra went to leave her life behind.

It was May 6, 2017. A turkey hunter was walking right through the area of Maple Lake around 7:15 a.m., when he noticed the body of a young girl hanging from a tree branch. He's the one who called 911. And to the detectives who first responded, they thought it was a pretty clear-cut case of suicide. When, in fact, it was anything but that.

Sgt. Josh Chappell: [at the site where Jchandra was found]: It was about right here where the rope was hanging off of the tree.

David Begnaud: What's it like to be back?

Sgt. Josh Chappell: It brings back a lot of memories. In my mind I can visualize Jchandra hanging in that tree.

When sheriff's officials arrived early that morning, there were the clues that Jchandra did not die here alone.

Sgt. Quin Fackrell [at the site where Jchandra was found]: There was two … grocery bags … just right over here on the ground. … When I went through everything, that's when I discovered a crinkled-up receipt … for a purchase of rope and on that receipt was Tyerell's name.

Detectives found a debit card receipt for the purchase of 20 feet of nylon rope from a C-A-L Ranch store with Tyerell Przybycien's name on it. Utah County Attorney's Office

It was a debit card receipt with the name Tyerell Przybycien.

David Begnaud: So, this was the first thing you saw that said, "I got to talk to this guy," right?

Sgt. Josh Chappell: Yeah. When we saw that receipt we knew that we needed to … contact Tyerell.

Also, in one of the bags was Jchandra's note pointing them to a cell phone video.

Jchandra's note read in part: "My name's Jchandra Brown and I hated my life. Goodbye f----d up world. Watch the video. It's on my phone."

Sgt. Josh Chappell: This was the phone that was left at the scene.

David Begnaud: Now her mom had taken away her phone.

Sgt. Quin. Fackrell: This was a spare phone that she had.

The phone could be the answer to many of their questions, but there was a problem.

Sgt. Quin Fackrell: I tried to power the phone on, it wouldn't power on.

Sargeant Fackrell decided to leave and charge the phone in his car while he drove back to Spanish Fork. And when it finally powered up …

Sgt. Quin Fackrell: That's when I saw … the video that was recorded at that time of the incident.

Sgt. Josh Chappell: This is a 10-minute video of … Jchandra dying.

Sgt. Quin. Fackrell: I was shocked. Absolutely shocked.

David Begnaud: What was so shocking given what you normally see on any given day?

Sgt. Quin. Fackrell: I was shocked for the fact that somebody could sit by and let somebody lose their life and not do anything.

Fackrell suspected that the person who bought the rope may have shot that video, too.

Sgt. Quin. Fackrell: He was obviously a person that we wanted to talk to.

Well, as it turned out, Tyerell found them first.

Sgt. Josh Chappell: I kind of look up the hill and I notice that there's somebody walking to us. … So, I actually walked back up the hill. … Immediately he tells me who he is … I recognize his name from the receipt.

David Begnaud: Why had he come back?

Sgt. Josh Chappell: His initial statement to us was he was going to make sure that Jchandra was dead.

Sergeant Chappell wanted to hear more. So, he suggested they ride together to the Utah County Sheriff's Office to continue the conversation.

David Begnaud: At that moment were you thinking of him as a suspect?

Sgt. Josh Chappell: No. I certainly thought that there might have been a crime committed. But what crime?

Sgt. Josh Chappell: As we drove to the sheriff's office we just talked generally about who he was and what his interests were.

Tyerell's mother Brittney Johnson says he always made her proud.

Brittney Johnson: He was a quiet kid. He always cared of others. He's very smart, very smart child. Was always ahead in his reading. Always ahead in his math. Loved science. … He was very active. Did a lot of sports. He tried soccer, baseball, basketball, wrestling.

Tyerell Przybycien and his mother, Brittney Johnson. Johnson said she never heard of Jchandra Brown before the teen's death. Brittney Johnson

But as Tyerell got older, Johnson started to see some changes in her son.

Brittney Johnson: He just pulled quite a bit of negative thoughts, um, into everyday life and it was shocking to me … so I took him to the doctor … was thinking he was depressed. You know, something is not right. … the doctor told me that he just is a pessimist. And that's [emotional] hard to be told.

David Begnaud: Did you know anything about Jchandra Brown before she died?

Brittney Johnson: I had never heard of her.

David Begnaud: Tyerell never mentioned her.

Brittney Johnson: No.

David Begnaud: Never saw him with her.

Brittney Johnson: No.

Tyler Hughes-Millman: Actually, I was the one who introduced her to Tyerell. … I told Tyerell, "Hey, I have a new friend." … And he said he wanted to meet her.

Tyler Hughes-Millman was good friends with both Jchandra and Tyerell.

David Begnaud: Did you ever know Tyerell to be depressed?

Tyler Hughes-Millman: Not really. He was a little bit depressed it seemed like sometimes, but he wasn't that bad.

Hannah Baldt: Jchandra … hung out with him all the time.

David Begnaud: What drew her to him?

Tyler Hughes-Millman: I actually have no clue. She liked hanging out with him a lot.

David Begnaud: Were Tyerell and Jchandra romantic in any way?

Grace Jackson: No.

Hannah Baldt: No, she did not see him as a relationship kind of guy.

Grace Jackson: She wanted to try and help him.

David Begnaud: She thought she could change him.

Grace Jackson: Yes. She thought that he could she could make him want to join other people and actually have fun instead of sitting by himself.

Sue Bryan: She knew when people were upset or sad. She would go up to 'em, talk to 'em and make 'em feel comfortable.

David Begnaud: Before Jchandra died, had you ever heard of Tyerell Prezbycian?

Sue Bryan: No.

David Begnaud: Not from her or anybody else?

Sue Bryan: Nope.

The Utah County Sheriff's investigators were about to get to know Tyerell very well.

QUESTIONS FOR TYERELL

On Saturday morning, May 6, 2017, hours after she reported her daughter Jchandra missing, Sue Bryan went to work. Not long after she got there, her manager wanted to see her. Sargeant Fackrell was waiting, too.

Sue Bryan: They had me sit down. … And he says, "Jchandra's gone. And she's not coming home." … I'm like, "Where's she gone to? Why? Where's she gone to?" … And then he said, "she's gone. … She's passed away. We found her in Payson Canyon."

Sgt. Quin Fackrell: She was devastated. As any parent would be. … Obviously, it's like … dropping a bomb on the family and it's not easy for them to process.

"Jchandra was my world. She was my life," Sue Bryan said. "When Jchandra died, my heart shattered." Sue Bryan

Sue Bryan [crying]: What I said was, "I should have loved her more. I should've gave her more love," because now I thought she'd completed suicide. I -- I didn't know. That's what went through my mind.

David Begnaud: So, suicide was the first thing you thought.

Sue Bryan: Yeah … All I could think was she's at the bottom of a canyon.

Just across town, Tyerell Przybycien was talking to sheriff's detectives, too:

SGT. JOSH CHAPPELL: So, what's your relationship with Jelly? TYERELL PRZYBYCIEN: I wouldn't say close friends, but, just, you know, we knew each other …

For the next five hours, Tyerell described just how Jchandra ended up in Payson Canyon the night before:

TYERELL PRZYBYCIEN [to Sgt. Chappell]: She kept saying, "I want to die. I want to die. Kill me. Kill me." So I eventually said, "OK, I'll make that happen for you."

Sgt. Quin Fackrell: He described how he got a text from Jchandra that said, "let's do this tonight."

TYERELL PRZYBYCIEN [to Sgt. Chappell]: So, Friday, I get off work, I get home, get a message from her.

Investigators would later discover that Tyerell and Jchandra had been texting each other for weeks about suicide.

David Begnaud: Once you get your hands on the text messages … what do they tell you?

Sgt. Quin Fackrell: That Tyerell had been planning this from probably the first week that he'd met her. … He had researched this. He wanted this to happen and he carried it out.

TYERELL PRZYBYCIEN [to Sgt. Chappell]: She said she was at work … I went to Wendy's, picked her up.

Sgt. Quin Fackrell: And they left and went to C-A-L Ranch and he bought the rope.

Tyerell Przybycien can be seen purchasing rope in store surveillance video. Utah County Attorney's Office

Store security video and the receipt found at the scene both show that Tyerell purchased 20 feet of nylon rope:

TYERELL PRZYBYCIEN [to Sgt. Chappell]: I know I'm guilty now because I bought everything for her. … [starts to cry] And I asked her right there too, "Are you sure you want to do this?" She said "Yeah."

Sgt. Quin Fackrell: And then the two of them proceeded to drive towards Payson Canyon.

SGT. JOSH CHAPPELL: You find the spot, did you help her wrap the rope around the tree? TYERELL PRZYBYCIEN: I did … Then we got done tying the noose, I kinda just like pulled on it, I was like, "OK, that's pretty tight."

"I started recording… and I said, "Please, please, please!" Tyrell told Sgt. Chappell. "I waited 10 minutes and I checked her pulse. … I just got out of there, I was scared out of my mind." Utah County Attorney's Office

Tyerell says that's when he picked up her phone:

TYERELL PRZYBYCIEN: I started recording… and I said, "Please, please, please!" … I waited 10 minutes and I checked her pulse. … I just got out of there, I was scared out of my mind. SGT. JOSH CHAPPELL: So at any time, did you try to talk her – talk her out of this? TYERELL PRZYBYCIEN: I didn't try to talk her out, I just said, "that's what you want to do. If this is what you want."

David Begnaud: Did he in any way try to paint this as a suicide pact?

Sgt. Quin Fackrell: He did.

But Sgt. Fackrell says Tyerell also told him several times that he had no intention of completing suicide that night:

DETECTIVE: You talked about her talking to you and you understood what it was like to be suicidal. And now, you're telling us that until you started talking to her, you were never suicidal? … How does that work? TYERELL PRZYBYCIEN: I was fascinated by death, OK ... DETECTIVE: That's the word I'm looking for. TYERELL PRZYBYCIEN: I was like, "this might be good."

David Begnaud: Are you then thinking that he's a suspect in a crime?

Sgt. Josh Chappell: Yeah.

David Begnaud: What's the crime?

Sgt. Josh Chappell: Well … possibly murder.

Possibly. But that wasn't their decision.

Ryan McBride: So I told the officer, I said keep digging … keep learning about what happened and the circumstances but if all we have is just him recording this and it's her act we might not have anything.

Deputy Utah County attorneys Chad Grunander and Ryan McBride were assigned to evaluate the case for possible prosecution.

Prosecutor Chad Grunander: Ryan was the initial contact with the county sheriff's office … I was a supervisor at that time.

From the start, they faced a unique challenge. In 2017, Utah had no law against assisted suicide.

Prosecutor Chad Grunander: We were one of only a handful of states in the country that did not have an assisted suicide crime. And, so, this was either going to be murder or potentially manslaughter or nothing at all.

Sgt. Josh Chappell: And that's when … another detective … sends me a text message … recovered from an acquaintance of Tyerell's. … "What would you do if you had a friend that wanted to kill themselves?" This friend said … "I would talk them out of it of course." And he responds back … "I would help them do it. Its [sic] like getting away with murder!"

Prosecutor Chad Grunander: When we got that message … it was very clear in our minds that he was acting intentional. He was wanting to help cause her death. … We felt like we had enough. That was the break for us.

Five days after introducing himself to Sgt. Chappell in Payson Canyon, Tyerell Przybycien was charged with first-degree murder. Utah County Sheriff's Office

Just five days after introducing himself to Sgt. Chappell in Payson Canyon, Tyerell Przybycien was charged with first-degree murder.

Sgt. Josh Chappell: He told us … later … part of his reasoning for going back to the scene … was … to want to make sure that she was dead. And then he had plans to collect the noose, the rope, and save it and keep it.

David Begnaud: Like some kind of souvenir?

Sgt. Josh Chappell: Like a souvenir or a trophy.

And there was something else Tyerell wanted the detectives to know.

Sgt. Josh Chappell: He described that Jchandra had written a note to her mother … and he left it in the mailbox outside the home.

Sue Bryan: I haven't read the note since the first time that it was read to me.

Sgt. Quin Fackrell: It was … your typical emotionally-charged letter, basically saying she's sorry.

Jchandra also wrote something else in that letter: "This was all my decision."

Prosecutor Ryan McBride: The question was, was this her decision or was this his plan?

JCHANDRA'S DECISION OR TYERELL'S PLAN?

David Begnaud: When you found out what he did. What was your first reaction?

Brittney Johnson: They have the wrong person. There is no way Tyerell would do anything like this.

Brittney Johnson says she never imagined she'd find her son in jail, awaiting trial for murder.

Brittney Johnson: I truly felt like I was living a nightmare that I would wake up from. I just couldn't process Tyerell participating in anything like this.

David Begnaud: Have you ever been able to ask him why?

Brittney Johnson: No.

Neil Skousen: In his mind I don't think that he was committing murder. He was helping her do what she wanted to do.

Neil Skousen and Greg Stewart were hired to defend Tyerell at his upcoming trial.

David Begnaud: How does this case compare to anything you've dealt with prior?

Neil Skousen: Nothing compares.

TYERELL PRZYBYCIEN: I feel guilty. I feel like I did murder her. That's what it is. DETECTIVE: OK. Why do you feel that way? TYERELL PRZYBYCIEN: Because I helped her so much, and that was my plan.

So how do you defend a case where your client seems to have already confessed?

Neil Skousen: We had the words of Jchandra. … In her suicide note she told her mom this was all her decision.

Prosecutor Chad Grunander: We could not escape the fact that Jchandra participated in her own death -- that she wanted to die. That was a real factor that we had to consider in prosecuting this case.

Dr. Harold Koplewicz: There's just no doubt that she was determined. That doesn't mean we couldn't just had another outcome.

Child and adolescent Psychiatrist Dr. Harold Koplewicz.

Harold Koplewicz: The leading cause of death worldwide for 15-to-19 year old girls is suicide. It's – it's unacceptable.

David Begnaud: Did she ever mention about talking with Tyerell about suicide?

Hannah Baldt | Jchandra's friend: No. Those were things that she'd keep to herself, mostly.

David Begnaud: Even though you guys were some of her closest friends.

Hannah Baldt: Yes. She -- everybody has their secrets.

Grace Jackson | Jchandra's friend: She didn't let anyone know.

Dr. Harold Koplewicz: When you read the texts, you start to think that this has become part of the game they play, except it's a very dangerous game.

In one of the texts Tyerell asks Jchandra: "You want the quick and painless, no chance of escaping or returning to this life?"

Jchandra responded: "I just want to die. I've been trying too long." "…I just want to make sure I end it."

David Begnaud: Do you think Tyerell was a negative influence on Jchandra?

Grace Jackson: Yes.

Hannah Baldt: Most definitely. … She'd get more and more depressed the longer she hung out with him. That was obvious. At least to me it was.

Dr. Harold Koplewicz: He was feeding her. She had these thoughts. She had these plans … And he was he was encouraging it. He was scratching the itch. And … it went further and further and further.

Grace Jackson: Without his support and his help for doing that, she wouldn't have been able to do it.

Hannah Baldt: She'd still be here.

Dr. Harold Koplewicz: I think it's true he didn't push her off the cliff. But he kept his arm around her and encouraged her to keep moving forward.

But would the prosecutors be able to convince a jury of that?

Prosecutor Chad Grunander: The prosecution … has the burden to show the necessary intent to commit a crime. And the best way to show that is through the defendant's own words.

And Tyerell gave them a lot to work with -- all of those text messages between him and Jchandra.

Prosecutor Ryan McBride: You have Tyerell talking about how he's gonna help Jchandra die. Different ways of taking her life. Recording her do it.

David Begnaud: This is a text that Tyerell sends to Jchandra: "Can I mutilate your body and cut your head off and dispose of your body?"

Sgt. Quin Fackrell: Yes. Very disturbing.

Prosecutor Ryan McBride: All these messages just add up to this depravity -- not caring about human life. And our argument is an intent to kill and a desire to participate in causing someone else's death.

David Begnaud: What was the most damning piece of evidence?

Greg Stewart: I think some of -- of the text messages that came out when he was talking about getting away with murder. … As … the father of a 15-year-old daughter and as a defense attorney … that was one thing that, that I guess … troubled me. … I wish those types of statements hadn't been out there. It would've made defending the case I think a lot -- a lot easier.

Neil Skousen: If we could keep our client's mouth shut that's really a big part of this.

But Tyerell still had a lot to say, reaching out to family and friends with letters and phone calls from jail.

Prosecutor Chad Grunander: He bragged about his conduct, his accomplishment, if you will. He talked about, when I get out, I want to get a noose tattooed all over my arm.

Prosecutor Ryan McBride: He asked a friend of his to set up an Instagram page and … use the media to enhance his notoriety and somehow profit off of this.

Tyerell also wrote that he wanted to get in touch with Michelle Carter. She caught the nation's attention during her precedent-setting trial for encouraging her friend Conrad Roy to kill himself. Tyerell wrote: "We'd get along great!"

David Begnaud: Did you ever pay him a visit to jail and say to him, "you have to stop writing?"

Greg Stewart: Every time we saw him.

Just weeks before his trial was set to begin, Tyerell reached out to his friends again:

Davis Begnaud [reading letter]: "I will encourage you to use your right to remain silent as anything you say is held against me in court."

Sgt. Josh Chappell: He writes a letter … telling them that they don't have to testify against him, they shouldn't testify against him.

Tyerell's letters to friends telling them they should not testify against him would lead to more trouble for the teen Utah County Attorney's Office

Davis Begnaud [reading letter]: "It would help my case if you'd inform everyone—that is subject to interrogation—to use their right to remain silent."

Prosecutor Chad Grunander: He was … telling them, essentially, to not cooperate with the police. You can't do that. That's witness tampering.

In fact, that letter changed everything.

Neil Skousen: Did we know that he would send out letters … that would hurt us down the road? No. Did it hurt us? Yes.

MORE TROUBLE FOR TYERELL

In the fall of 2018, the Utah County prosecutors and Tyerell Przybycien's defense team were getting ready for trial.

Greg Stewart | Tyerell's defense attorney: Tyerell had been adamant about going to trial.

David Begnaud: What was his thought process?

Greg Stewart: That … he hadn't committed murder.

Prosecutor Ryan McBride: I'd planned my closing argument. … Chad had planned a lot of his opening statement. We had our trial strategy.

David Begnaud: And then he changed his mind.

Prosecutor Chad Grunander: Well, I think one thing that changed his mind was an additional case that we filed against him for witness tampering.

After prosecutors found out that Tyerell asked his friends not to testify against him, they charged him with witness tampering in addition to murder. And that's when Tyerell asked for a deal.

Prosecutor Chad Grunander: We sat down and talked … and they asked us if we were open to a plea deal. We said, certainly, if we think it satisfies the interest of justice.

This was the deal: Tyerell would plead guilty to a lesser first-degree felony of child abuse homicide.

Prosecutor Chad Grunander: Murder was 15 years-to-life. We compromised and offered … child abuse homicide, which was five-to-life.

David Begnaud: Why the about-face? Why the change?

Greg Stewart: I think it was … thinking more clearly about the situation and realizing the predicament he was in.

JUDGE AT PLEA HEARING: Mr. Przybycien, as to … the amended charge of count one, child abuse homicide … what is your plea TYERELL PRZYBYCIEN: Guilty.

David Begnaud: What did you think when Ty pleaded guilty?

Hannah Baldt: I wasn't surprised.

Grace Jackson: I'm glad. I'm glad that he fessed up. I'm glad that he didn't try and keep denying it.

Sue Bryan: It was child abuse. He did take a child. And in my eyes … child abuse homicide is as bad or worse than just murder.

Six weeks later, Tyerell was back in court for sentencing. As statements were read, it was clear how many lives had been damaged by this one event:

GREG STEWART | TYERELL'S ATTORNEY: Obviously, Tyerell has made some -- some poor decisions in his life. … May 6th was a day I'm sure he wishes he could, could undo. HANNAH BALDT | JCHANDRA'S FRIEND: She was the brightness to anybody's day. BRITTNEY JOHNSON | TYERELL'S MOTHER: Tyerell always cared for others more than himself. … I am truly sorry for the loss of Jchandra. … I wish we could all go back to that day and get a do-over, but I know that we can't.

Sgt. Quin Fackrell: Two families now have been torn apart. … I feel really bad for the Przybycien family. I really do. They lost a son. … And I've always felt bad for the Browns. They lost their daughter.

DUSTIN LEWIS | JCHANDRA'S BROTHER: There's a hole in our lives and our hearts that she used to fill, and we suffer greatly without her. SUE BRYAN | JCHANDRA'S MOTHER: I believe there will never be true justice for Jchandra, because Jchandra will never get to come home to me.

Dr. Harold Koplewicz: If you listen to this story, what makes you cringe is the fact that there's so many missed opportunities to help her. So many missed opportunities to change the outcome.

PROSECUTOR CHAD GRUNANDER: It is clear -- very clear -- that Jchandra's death was avoidable.

Before the judge handed down his sentence, Tyerell was also given a chance to speak:

TYERELL PRZYBYCIEN: I would like to directly apologize to the victim's mother, Sue Bryan, for my irresponsible and irrational behavior … What I did I am not proud and it doesn't deserve pity.

As a result of this case, the state legislature passed a new law, which now includes assisted suicide in its definition of manslaughter. The-Salt-Lake-Tribune/Scott-Summerdorf

Judge: Mr. Przybycien … you were charged with child abuse homicide, in which you plead guilty to. … I'm required by law to sentence you to an indeterminate sentence of not less than five years, but which may be for life.

Tyerell is now serving out his sentence at the Utah State Prison in Draper. As a result of this case, the state legislature passed a new law, which now includes assisted suicide in its definition of manslaughter.

Greg Stewart: Assisting somebody, providing the means or the opportunity to help somebody kill themselves, is now a second-degree felony in the state of Utah.

David Begnaud: Is this justice for Jchandra?

Sue Bryan: Justice for Jchandra would be he didn't do it. He didn't record. He stopped and saved her.

Dr. Harold Koplewicz: I think I think it's completely understandable that her parents and her friends blame him. But in the same way that I don't think we would have this outcome without Ty, I don't think we'd have this outcome without Jchandra.

David Begnaud: So, what's the takeaway?

Dr. Harold Koplewicz: I think the takeaway is that we have to take this more seriously … when kids start having difficulty at school, when they are changing their behavior, when you start to suspect that something is wrong, that we take it seriously.

Sue Bryan: Love your family, love your children. … If they're sad, find out if they need help. Ask every day. Ask them questions. … Those are the things I regret that I didn't do with Jchandra.

David Begnaud: Have you identified one thing that works better really than anything else at stopping someone who is right on the brink?

Dr. Harold Koplewicz: So, I think that's a very important question because, remember, if you're a teenager, you feel terrible for the moment. And if you find someone who says to you, "Stop, wait, let's think about this. It's not that bad. I'm sure I can help you get out of this."

But Jchandra never got that help from Tyerell.

Dr. Harold Koplewicz: This is an unacceptable outcome. Suicide is not acceptable. That has to become the nation's thought about this. That suicide, particularly in teenagers, is not an acceptable outcome. … You're not supposed to die when you're 16 years of age. And especially … by suicide.

Jchandra Brown Dustin Lewis

Jchandra Brown was returned to her hometown of Twin Falls, Idaho. She is buried near her great-grandmother.

David Begnaud: Do you ever think you could forgive this man?

Sue Bryan: My faith says that I should forgive him. … My heart says how could you forgive someone and just accept I'm sorry. I'm sorry that I made a bad decision and that I took … your beautiful, loving, kind daughter away from you. … How -- how can someone forgive someone for what he did.

HELP IS AVAILABLE

If you are thinking about suicide or know someone who is, please call the National Suicide Prevention Lifeline at 1-800-273-8255

You can also reach out to the Crisis Text Line --a free, 24/7, confidential text message service for people in crisis. Text HOME to 741741