'Lost at the Science Fair': Kyron Horman's disappearance remains one of Oregon's biggest mysteries

The 2010 disappearance of 7-year-old Kyron Horman remains one of Oregon's biggest mysteries.

On the day Kyron vanished, he was driven to school by his stepmother, Terri Horman. Normally Kyron would take the bus, but on June 4 there was a science fair, and he needed a ride to transport his red-eyed tree frog project to the Skyline Elementary School in Portland.

After setting up at the fair, the last known picture of Kyron was captured. A beaming second grader, standing proudly in front of his science project.

Kara Robinson Chamberlain, a true crime influencer, kidnapping survivor and former law enforcement officer, went to Oregon to investigate the case for the new docuseries "Somebody Knows Something."

The fifth episode of "Somebody Knows Something," "Lost at the Science Fair," premieres Monday, Aug. 31 at 10 p.m. ET/PT on Freeform, and streams the next day on Disney+ and Hulu.

Kyron's mother, Desiree Young, was living four hours from Portland in Medford, Oregon, when Kyron disappeared. Over the last 16 years, she has remained outspoken, hoping that somebody knows something about what happened to her son.

Young, who had been divorced from Kyron's father Kaine Horman long before the boy went missing, told Chamberlain her son "was very shy and reserved. If he knows you and he trusts you, he'll be his funny self around you. I think of him dancing and being goofy."

Kaine Horman, Kyron's father, had custody of the boy when the second grader vanished.

Young recalled being heartbroken over the arrangement and told Chamberlain that she originally had custody of Kyron, but that changed when her son was 2.

"Kaine finally had him for an overnight and I got a kidney infection, and I was in the hospital. So I signed over temporary custody for a couple of months," she said. "Unfortunately, because of my significant medical bills and the fact that I did not earn as much money as Kaine, I did not get custody back."

The last time Young spoke to her son was the night before he went missing, she told Chamberlain

"Kyron was very excited about what was going on at the science fair," she said. "So I was shocked when the school secretary from Skyline Elementary called me and said 'I have to notify you that he's missing.' And I remember thinking, what the hell is going on? And I said to her, 'I'm getting in the car.'"

Kyron's disappearance sparked the largest criminal and search operation in Oregon's history. Chief Deputy Lance Hemsworth, of the Multnomah County Sheriff's Office, told Chamberlain that the initial information about his disappearance came to the sheriff's office when an employee at Skyline Elementary noticed that Kyron was missing from school.

Kaine, Kyron's father, recalled law enforcement not giving them much information initially. He was married to Kyron's stepmother, Terri Horman, at the time.

Terri said that she last saw Kyron walking down the hallway towards his classroom before she left the school.

"It was all about them pushing us, because we were parents. Statistically, one of us had committed the crime, and they weren't there to be friendly. They were there to get answers. They asked us to take polygraphs, we all did," he told Chamberlain. "I wasn't guilty of anything, so it was easy to go do it. They were asking us independently what our steps were that day. I figured that everyone else who had to take one would pass. Terri failed that polygraph."

Carson Lopez, who was 7 at the time and one of Kyron's best friends in 2010, was at school the day he disappeared. He said Terri came over to them and told Kyron that she had to take him to a doctor's appointment right away.

Kaine said he knew nothing about a doctor's appointment, but acknowledged that things were difficult with Terri at home in an interview with Chamberlain.

"We were having some troubles. It wasn't stable all the time. But she was one of the last people I would think would do anything, especially with all what we had been through," he said. "It was all of us together, her son, Kyron and our daughter, who was 18 months old at the time. But Terri being involved in Kyron's disappearance didn't cross my mind until she went back for another polygraph that she also failed."

A few weeks after Kyron's disappearance, Terri faced bombshell allegations that she tried to hire someone to kill Kaine. In court paperwork for a divorce, Kaine noted the alleged plot and also claimed that Terri may have been responsible for Kyron's disappearance.

Kyron's mother, Young, also suspected that Terri was lying to her about what happened to Kyron and wanted her to fully cooperate with the investigators. After Terri hired a lawyer and stopped cooperating with authorities, Desiree filed a civil suit as an investigative tool to depose her and others to get information.

Ultimately the case was dropped after a friend of Terri's invoked the Fifth Amendment 147 times during questioning about her whereabouts the day Kyron went missing, as well as her interactions with Terri that day.

In spite of Desiree's civil case unraveling in 2013, public suspicion continued to follow Terri. In 2016, she appeared on ABC News' "Nightline," where she was asked if she had anything to do with Kyron's disappearance.

"No. None. And I don't resent you asking that question, but it hurts my heart to even be asked," she said. "Every sense of the word, he's my son."

She also had an explanation for the polygraph tests.

"I'm deaf in my left ear. I'm reading your lips as we're speaking. Also, I hadn't slept. I hadn't slept in days," Horman told "Nightline."

She also said that authorities had settled on her as "their patsy" and denied ever asking anyone to kill her now ex-husband Kaine.

Terri has never officially been named a suspect in this case. She maintains her innocence to this day.

Chief Deputy Hemsworth believes someone in the community knows what happened on June 4, 2010, and is "asking that person to come forward, because it has the opportunity to provide some measure of peace to a family that's carried this burden for so long."

As of May 2026, police have digitized the Horman case files and are using artificial intelligence to examine new and existing leads.

For Desiree, it's been a long 16 years and every time the phone rings, she hopes that it's Kyron.

"Even though this much time's passed, I think people have to realize this is still June 4 for all of us," she said.

Through her attorney, Terri Horman declined an invitation to do an interview or comment on any of the allegations against her.

For additional reporting and discussion about the case. Join us live on the "Somebody Know Something" Youtube channel.

Anyone with information about the case is urged to contact the Multnomah County Sheriff's Office at 503-988-0560.