Nineteen-year-old Katelin Akens was always unique, quirky, unpredictable and emotional, and like any teen, always attached to her phone.

"We talked every day," said Katelin's friend Kevin Eastridge. "She is the one person that I could tell everything to, and I think the same went for her too."

The outgoing teen's romances were as devil-may-care as every other part of her life, leading her from boyfriend to boyfriend, and even to a girlfriend and eventual fiancée named Amber. It's true love, and Katelin travels across the country to be with Amber in Arizona, and a new life far from her hometown in Virginia.

But there was one thing that sent her running back home: Her sister Gabby gave birth to a baby boy. Katelin returned to Virginia in December 2015 to hold her new nephew. But the turnaround had to be quick

"She was going to stay longer but she was supposed to start cosmetology school on the 7th," said Lisa Sullivan, Katelin's mother.

But Katelin's trip back to Arizona would hit a disastrous roadblock, which started with her ride to the airport.

"Katelin was supposed to leave December 5th at like 5:40 p.m. I had to work, so I wasn't able to take her. So my last resort was calling my ex-husband," said Lisa. "Last resort."

Lisa's ex-husband helped raise Katelin and her younger sister Gabby, but Katelin's friends say life with stepfather wasn't always smooth sailing.

"She flat-out didn't trust him," said Kevin. "She felt very nervous around him, and that he was kind of abusive to an extent. I can't confirm physical because she never outright told me, but definitely verbally."

Those allegations have never been substantiated, and Katelin never filed charges of abuse against her ex-stepfather.

And 9:20 on Saturday morning, the day she went missing, hours before Katelin's flight at 5:40 that night, Lisa dropped Katelin off at her ex-husband's residence.

"I talked to him to make sure it was OK and let him know what time her flight was leaving and stuff like that, and he was like 'Yeah, that's fine,'" said Lisa. "He says 'I have to be at work at 3 that day so she'll just be dropped off a little early.' I'm like 'That's fine.' He said 'OK' -- and it never happened. She never made it to the airport."

In a text at 1:52 that afternoon, Lisa's ex-husband said Katelin asked to be dropped off at the Springfield Mall Metro Station, two stops from Ronald Reagan Washington National Airport in D.C. It's an odd request.

"She's never really been on the Metro before since she was like 6, 7, so I don't know why he would do that," said Lisa. "He just said 'Yes, he was gonna do it.'"

Then a series of puzzling text messages appear. At 2 p.m., only eight minutes after the ex-husband says he dropped Katelin off at the mall, Lisa receives a message from her daughter's phone: "I'm at the airport. Battery dying so won't be able to text for a bit."

But then Lisa learns that Katelin had sent her fiancée a peculiar message at 11:56 a.m.: "Something came up. I'm not coming back today. I'll let you know when I get a new flight. I won't be able to text for a bit."

"I got nervous when Amber had texted or messaged me saying that Katelin wasn't coming home, she needed a new flight, something was wrong with her flight, and I was like 'What do you mean? She said she was there,'" said Katelin.

Then at 7:15 p.m., two hours after missing her flight, a final text from Katelin to her mother Lisa. The message is simple, but maybe the most disturbing: "I'm staying with a friend. I need some time alone."

"It didn't sound right. It didn't look right because it was two messages," said Lisa. "And she doesn't do that. She'll wait for you to respond, and then she'll send another one. It wasn't her style."

Those messages would be Katelin's last. But it wouldn't be the last sign of Katelin.

Two days after she disappeared, a carry-on suitcase is discovered in the woods of a rural road 44 miles away. It's Katelin's. And what's inside may put a different spin on the entire case.

"She wouldn't answer texts, wouldn't answer phone calls," said Lisa Sullivan, Katelin Akens's mother. "It was like that until her phone stopped working."

Katelin has now been missing for more than a year -- but not without a trace.

"They a worker had found her luggage on the side of the road," said Lisa. "They said it looked like it was tossed out the window."

At the Spotsylvania County Sheriff's Station, a deputy presents Lisa with the luggage, a blue canvas carry-on.

"Me and Gabby looked at each other and we were like, 'We're never going to see her again,'" said lisa.

But the suitcase only brings up more questions, starting with what's in the suitcase, and what's missing.

"What was missing was her clothes, her phone and her high school diploma," lisa said.

That's it. Everything else -- wallet, cash, debit cards, even her plane ticket home -- are still packed neatly in the case.

But how in the world did her bag get so far from where Katelin's ex-stepfather says he left her?

"Katelin does not drive either, she's never had a license, she's only had identification cards," said Lisa.

Police want to know too. They examine location records from Katelin and her ex-stepfather's cellphones. Police say those records tell a very different story than the one her ex-stepfather is telling.

At 1:56 p.m. on the day of the disappearance, Lisa got a text from Katelin's phone that said "I'm at the airport. Battery dying so won't be able to text for a bit." But at that exact time, police say, Katelin's phone actually "pinged" at a location more than 30 miles from that Springfield Metro stop.

When Lisa's ex-husband messaged Lisa at 2 p.m. saying he dropped Katelin off, police discover his phone pinged close to his home, nowhere near the airport or the mall.

What about Katelin's final text, saying she "wants to be alone"? Police say that's when Katelin's phone pings off a cell tower in Stafford, less than 15 miles from where her luggage was found.

"Whoever sent that message, 'cause we don't know if it was her or not, has sent Amber a message, and then me a message, and that was the last bit that was on her phone," said Lisa.

According to Lisa, police believe Katelin never left the area around her former stepdad's house.

Was there foul play in Katelin's disappearance? And authorities are wondering, Did her stepfather, now being called a person of interest, potentially have a hand in it?

Allegedly fudging his whereabouts is just the beginning of the stepdad's inconsistencies. Lisa claims he told her he had to work Saturday at 3. But Lisa finds out that in fact he never showed up at the office.

Katelin's mom says police told her they searched his vehicles, his computers and confiscated his cellphone.

"They didn't find anything in his vehicles, and he won't give up his password for his phone for them to get into it, so he won't give them the unlock code, so that's still waiting to get looked at," said Lisa.

What's more, police say he initially agreed to take a polygraph test to clear his name.

"It was that day that had come up to his polygraph, he said no, he called the detective and said no," said Lisa. "He said 'It's not gonna help me so there's no point in me doing it.'

"I don't know why he still won't take it," Lisa said. "I asked him in December if he'd go take the polygraph test and start talking. He still refuses."

Raymond Gemma, the private investigator who joined Lisa Sullivan in her desperate search for Katelin Akens, isn't willing to "open-and-shut" the case on Katelin's former stepfather. He proposes another possibility.

"I'm not sure anybody has determined whether or not Katelin ever got into the ex-stepfather's vehicle," said Gemma.

"Again, it's speculation, but a potential theory is that Katelin may have ran away, and he knows about it and she left her suitcase there and didn't tell him she was doing it," said Gemma. "She could have left without him even knowing. That's a potential theory and once he found out she's missing, it was kind of like an 'Oh crap' moment for him: 'Oh my God, her suitcase is here, I have to get rid of it.'"

That theory has never been substantiated. In fact cops won't say how they think Katelin's suitcase ended up in the woods. But what could prompt Katelin to suddenly "ghost" her friends and family?

"They can't tell if it's foul play or if she left on her own, they said they're still investigating both ways," said Lisa Sullivan, Katelin Akens's mother.

There's a text conversation that may hold the key, and it starts with Katelin's words: "I just really need someone to talk to."

"She had messaged me and told me what happened," said Katelin's friend Kevin Eastridge.

What happened is a twisted tale of seduction and sex.

Katelin pours her heart out to her good friend Kevin about the night before, when she partied hard with a female friend from high school and that friend's boyfriend.

"It's kind of a hard thing to describe, really," Kevin said. "From what she told me, they were all drinking together and then they proceeded to, how do I phrase it -- I guess they kind of forced themselves onto her."

Katelin confesses the party quickly got out of bounds.

She writes, "Her boyfriend got me really really really drunk and then she kissed me and then he kissed me. They did everything to me and each other."

Katelin tells Kevin she spent the next morning wracked with guilt.

"She felt guilty, she felt like she had cheated on Amber, I guess you could say, and she felt that she was, I guess, a bad person for doing it," Kevin said.

Some of Katelin's final messages: "I don't know how to feel or anything. I've been depressed and crying all day."

It's in that guilt-ridden state of mind that Katelin heads home to Arizona and her fiancée. But did she run away in shame? Or did something much worse happen to Katelin? Was she suicidal?

"Not to my knowledge, no," said Kevin. "She was never a person to me that gave up on life. She always tried to fight whatever she was feeling, and like I said, that's why she came to me. She would come to me because she was trying to fight that."

Crime Watch Daily is tracking down one person who may know more about whether Katelin was winning the fight, a man police call a person of interest -- Katelin's ex-stepfather. He was the last known person to see her. So we want to ask him to shed some light on that day. Was Katelin acting strange? Why did he drop her off at the mall to begin with? At his residence, he declined to appear on camera, and left the premises.

Katelin's ex-stepdad has never been charged in her disappearance. And citing the ongoing state of the investigation, police denied our request for an on camera interview, saying: "We are still actively investigating this case and are working closely with the FBI Behavioral Analysis Unit."

Private investigator Raymond Gemma has similar concerns about leaking confidential info that could compromise the case.

"There is circumstantial evidence that points in one direction. But I can't say which direction," said Gemma. "It's an ongoing investigation. Criminals watch the show."

That leaves Katelin's family and friends at a standstill, wondering where she is, if she's OK, hoping she'll return.

If you saw Katelin Akens on the day that she disappeared, or have any information on where she might be, you are asked to contact the Spotsylvania County, Virginia Crime Solvers at (800) 928-5822.