In the Mexican border town of Agua Prieta, Sonora, 3-year-old Omar Vargas went missing.
23 years later his disappearance remains a mystery. His father, Ismael Vargas, says he can still picture his son's face.
"He looked just like his mother but his face and smile were all mine."
Ismael Vargas immigrated to the US decades ago and settled in Chandler, Arizona. That's where he met his wife Mirriam Rivera at an Evangelical Church where they later married.
Both of them had children from previous marriages but they had Omar together.
On April 22, 1995, Ismael Vargas, Mirriam River, their son David and Omar all traveled to Agua Prieta, Sonora for an Evangelical Church conference.
"There were many people and we went there to see friends we hadn't seen in quite some time. That's where it happened."
After arriving, Ismael Vargas says their son David stayed inside the car as he, his wife and Omar began greeting the people in attendance.
While at the conference a neighbor across the church says they remember seeing Omar playing with other children, including their own, outside the church.
At one point, Consuelo Galaz says she and her husband saw all the children come to their home asking for water.
"And all the kids came inside, including my son...and my husband talked to all of them. I remember Omar was wearing a dress shirt with his little boots. He was dressed up like a cowboy."
Minutes later, Galaz says all the children were called to come back to the church and says they all got up including Omar and headed back.
"Moments later we heard all this noise outside with police and a woman crying. We went outside and the dad came up to us and asked if we had seen Omar. My husband told him that we had."
Two days after his disappearance, the Cochise County Sheriff's Office was alerted by a member of the family and the Agua Prieta Police Department also wrote them asking for help in the investigation.
According to the sheriff's office, search and rescue crews, deputies, the FBI, tracking dogs and a helicopter all went into Mexico to try and find Omar.
The dogs picked up a scent from a ranch a few miles away from the church but Omar wasn't found.
Several months later, Omar's mother died while searching for him after an accident on a Mexican highway.
Omar's case remains open and unsolved, awaiting future leads. His father says he hopes no other fathers ever have to live through losing a child.