When shards of bone were discovered in Aruba a few years ago, Dave Holloway hoped against hope that DNA testing would prove the remains were of his daughter, Natalee Holloway, who went missing in 2005 while on a high school graduation trip to the Caribbean island. It would be sad, and it would be disturbing, but at least it would be an answer in a case that remains largely composed of questions.

It took a year and a half of working under the radar with the help of an informant to locate the spot where the remains were found, behind a house that had been previously mentioned over the course of the sporadically eventful investigation.

"We've had a number of disappointments and I've put up a wall trying to find something that's not gonna disappoint me," he said on Today in August 2017. "And when we determined that these remains were human, I was shocked, and I know that there's a possibility this could be someone else, and I'm just trying to wait and see."

But that October it was revealed that the mitochondrial DNA wasn't a match to a sample provided by Natalee's mother, Beth Holloway. The bones didn't belong to Natalee.

Another dead end.

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"Out of the four individual bone samples only one was found to be human," forensic scientist Jason Kolowski, who tested the samples, explained to Oxygen, which chronicled Dave's journey with private investigator T.J. Ward as they followed what felt at the time to be their most promising lead in years.

"We don't know if the person is male or female," Jason added. "We don't know how old that person is. We don't know how long that person has been dead."

For nearly 16 years, the investigation into Natalee's disappearance has carried on in fits and spurts, with light occasionally appearing at the end of the tunnel, only to be snuffed out at the first whiff of closure. In the meantime, books have been written, Lifetime made two movies about the case, news-magazine shows have covered it top to bottom, and every theory in the book has been floated-including that Natalee is still alive, or at least was for years after the events of May 30, 2005, transpired.

Whatever those events were, exactly.

Despite all the media attention and so many law-enforcement hours spent trying to find out what happened, definitive answers have remained out of reach. But numerous times, authorities and Natalee's family seemed to be getting closer. "We always felt like with every lead, with every tip, it was always as if we were about to get her," Beth previously told 20/20. "They just always turned up nothing."

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Meanwhile, the family of Natalee has had to do everything in its power not to feel trapped in a different sort of prison.

In January 2012, the day before Joran was sentenced to 28 years in prison, a judge declared Natalee legally dead—a necessary move so Dave could access the money he had put into her college fund in order to pay for her younger brother's tuition. He needed a death certificate. "I guess most people do look at anniversaries, but I still think about it every day,'' Dave, who in addition to his and Beth's son Matthew has two other daughters from his second marriage, told Al.com in 2015 as the 10th anniversary of Natalee's disappearance approached. "That's something you'll never get out of your mind."

"The emotional trauma has a way of healing, and a person doesn't realize it until time goes on," he said. "When something comes up significant, you fall back down into that emotional state of trauma. I try to avoid those things as much as I can."

"I look back on it and I wonder how I even made it through," he added. "You're always thinking we're going to get an answer quickly and it never comes. I never dreamed it would be 10 years, and we would not have a solid answer."

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As for Beth, she told Today in 2016, "I have my answer as to what happened to Natalee, and he's sitting in prison in Peru... Justice is being served for Stephany Flores, thank God. And he is in prison in Peru. But justice has not been served for Natalee."

Beth has credited her faith for helping her accept her loss, and she eventually returned to work as a speech therapist at schools in Cullman County. She also traveled the country speaking publicly about Natalee, grief, her family's journey and how to look out for one's personal safety.

"It's a message of hope, and my definition of hope is that inexplicable empowerment that enables us to move successfully from challenge to resolution with courage," she told B-Metro magazine in 2015. "It's more than just wishful thinking. It is real that there is light at the end of the tunnel. No matter what you're trying to find your way through—It could be loss of a loved one, it could be terminal illness, it could be a financial loss. It's a powerful inspirational message that I share that teaches perseverance and hope and that you can endure."

Going back to Aruba in 2019 was painful, but also cathartic. She has long since accepted that missing Natalee is a part of her daily life. "Every time I looked out at the ocean [on other trips over the years], I couldn't handle it. It just disturbed me greatly," Beth told 20/20. "Because it made me feel as if I was never going to get an answer as to what happened to Natalee. But I feel like I have accomplished a huge feat… I can come back now to Aruba. I can get in the water... It feels great."

She added, "You're never going to get over the...loss of losing your loved one. But life does move on. Natalee would want us to enjoy what life we have left."

(E!, Oxygen and NBC are all members of the NBCUniversal family.)

(Originally published May 30, 2019, at 3 a.m. PT; updated Nov. 23, 2019, at 12:30 p.m. PT)

All the Leads That Proved to Be Letdowns in the Natalee Holloway Case originally appeared on Eonline.com