A retired U.S. Army veteran is still piecing together the disappearance of his geologist son years after he vanished from an Arizona work site, with new investigators looking to break open the four-year-long cold case using fresh forensic evidence. 

Daniel Robinson, 24, vanished after leaving work at approximately 9 a.m. on June 23, 2021, as reported by the Buckeye Police Department. Later that day, Daniel’s father, David Robinson, reported him missing after receiving outreach from his coworkers, who informed the family that Daniel had not returned to work. 

“When I first called in, [authorities] made me hang the phone up, wait two hours and call back,” the elder Robinson told Fox News Digital. 

The two men formed a connection through the disappearances of their children, leading Petito to travel to Arizona in April of this year to aid in the search for clues related to Daniel’s disappearance. 

“He called me in January and said, ‘Dave, I want to be a part of the search,” Robinson told Fox News Digital. “He said ‘I don’t want it to be about Gabby. I just want to come in as a friend to come out here to help you.’”

Petito is celebrating the resurrection of evidence in Robinson’s case, telling Fox News Digital the addition of new investigators is “fantastic.” 

“I really pray for him and his family,” Petito said. 

Robinson continues to advocate for missing Americans throughout the country, and he is pushing for new legislation to create federal standards regarding law enforcement’s response to missing-persons reports while running for a seat in South Carolina’s Second Congressional District. 

“The only thing that kept me straight is my love for my son and my military training,” Robinson said. “I had to rely on military training to look at my son as a mission, and I put the mission first.”