Kyron Horman was last seen in his school hallway in Portland, Oregon, over 15 years ago. His disappearance sparked the largest missing person search in Oregon’s history, and it remains one of the state’s most perplexing mysteries. Now, investigative reporter Kristin Thorne takes a closer look at the unsolved case as part of the new true crime video series, In Touch Investigates.

“We’ve been involved in several searches relating to this case, and it’s a case that obviously dates back now more than a decade, and the circumstances surrounding this case alludes to some areas that are some really difficult terrain to search and also to some individuals involved that we believe had something to do with his disappearance,” Doug Bishop, who works with United States Search Corps, exclusively tells In Touch amid renewed search efforts.

On the morning of June 4, 2010, Kyron arrived at Skyline Elementary School in northwest Portland with his stepmother, Terri Horman. He was excited to present his science fair project. Terri took a photo of 7-year-old Kyron in front of his display capturing what would become the last known image of him. Terri later reported that she left the school around 8:45 a.m. and that she last saw Kyron walking down the hallway towards his classroom. However, he never arrived. Later that afternoon, when Kyron didn’t return home on the school bus, his parents contacted the school.

The school told them Kyron had been marked absent, and the school called 911. Later that night, the FBI was notified. The search for Kyron became the most extensive in Oregon’s history, involving local, state and federal agencies. Despite exhaustive efforts, no trace of Kyron was ever found.

“I’ve been involved in multiple searches in the Columbia River area near there,” Bishop tells In Touch. “This is south of the Skyline Elementary School area where he was last seen, where he went missing from, and also in an area where one of the suspects in the case, their cell phone pinged nearby in a timeframe where we believe something happened to Kyron and there was a disposal process that was being played out with those who are involved.”

Despite the case being over a decade old, Bishop believes there are areas that can still be searched for answers regarding Kyron’s disappearance.

“This is definitely a case that we believe specific types of searching further, searching further searches can possibly be fruitful in finding Kyron,” Bishop continues. “However, this is also a sensitive case where we have to respect the fact that the district attorney is now keeping it an open case and also working with them.”

Bishop adds that it helps that new district attorney, Nathan Vasquez, has recently been elected in Multnomah County.

“He’s only been in office for a few months during his campaign. He was very outspoken with all of us that are very close to the case that he’s going to pursue the case and take it very seriously,” Bishop explains.

Even though Kyron’s case is unsolved, it’s still open. Law enforcement agencies continue to seek information that could lead to a breakthrough and there’s even a $50,000 reward for information leading to Kyron’s whereabouts.