A clean-cut man with smooth, brown skin, a double chin and wide, expressive eyes, Reyes worked for Battalion 316 from 1982 until he fled Honduras in 1988, after he and one of his sons were shot at from an unmarked car.
He was interviewed by The Sun in Brockville, Ontario, where he lives with his wife and five children. Reyes drives a taxi.
In 1980, Reyes was appointed chief of motorcycle police in San Pedro Sula. In Honduras, the police are a branch of the armed forces.
His mentor was General Alvarez, the head of the Honduran armed forces who created Battalion 316.
"I admired him," Reyes said. "He dressed very neatly. He wanted to build a professional institution. He was very decent with me. He made me feel very good. I thought the doors to my future were open."
Reyes said that his loyalty to Alvarez led him to agree to collaborate with the unit.
"They wanted to capture a group of terrorists that were infiltrating Honduras, and all I had to do was easy -- stop the vehicle and they would capture them," he recalled.
"As a policeman, I felt it was very important to comply. But later I noticed that these people were not terrorists," he said. "I thought they would be like, Syrians, but the prisoners were Hondurans.
"I thought the prisoners would be interrogated, but later I noticed that Battalion 316 was killing people."
Reyes said bodies began appearing "in rivers and in the banana fields." He said he was so shaken by Deras' murder that he went to Alvarez to report it.
"I said, 'I know someone who killed someone,' " Reyes recalled. "He said, 'Why did they involve you in this?' And he said a soldier must always be loyal and never speak against his superiors.
"He told me, 'What you have seen, you have to take to your grave.'"
Unearthed: Fatal Secrets