Nancy Ng has not been seen since October 19, when she reportedly went on a kayaking trip with others from the retreat.
His family hired professionals to help with search and rescue efforts around Lake Atitlán.
But the leader of the initiative says he is having trouble getting answers from witnesses – some of whom have since returned to Southern California – and suggests there is a need for a criminal investigation into her disappearance.
The FBI and State Department have been in contact with Guatemalan authorities regarding this matter.
His family is simply pleading for anyone with information to come forward.
“I miss my Nancy very much,” said her mother, Stephanie Li. “And I hope the government helps us find answers and bring her home.”
Nancy works for the Alhambra Unified School District. This was her second year going on a yoga trip.
Private teams scoured the area around the lake from the air and below the surface, but found no sign of Nancy.
A GoFundMe has been created to help fund these research efforts.
The leader of that effort told Eyewitness News that the failure of potential witnesses to provide more information led him to ask criminal authorities to be involved in the investigation.
Chris Sharpe of Black Wolf Helicopters, based in Guatemala, says he has searched most of the lake without any clues to Nancy’s disappearance. At this point, he starts to wonder if she really went kayaking on the lake.
“To me, this now becomes a criminal investigation because the witnesses who were there at the time of the incident have not come forward,” Sharpe told Eyewitness News.
The family doesn’t know why witnesses aren’t more cooperative.
“We’re begging you: If anyone sees anything that could help us, just let us know where to look,” said Nancy’s sister, Nicky Ng. “Because we need answers.”