Stevens, 70, said she grew concerned about her son in February 2017, as the two never went months without speaking. If he was in the United States, they would speak at least once a week and if he was out of the country, he would check in with her once or twice a month, she said.

By April 2017, when she could not reach him on his birthday, she said she knew something was wrong. Voicemail messages to his phone went unanswered, she said.

Stevens said she called the Glenn Heights and Dallas police departments to file a missing person report.

“They asked how old my son was and I told them and they said, ‘You can’t make a missing person report for a grown up,'” she said.