A very recently-retired federal agent who played a leading role in the capture of “El Chapo” 16 months ago said that U.S. officials knew of possible prison escape plans by associates of El Chapo, practically from the time he was back in prison.

“There was always chatter that there was going to be a breakout plan,” the source, an ex-DEA agent, told ABC News.

The source said that U.S. law enforcement would regularly pass on credible intelligence to Mexican officials, but that did not appear to help prevent Saturday night’s escape.

The source was “saddened but not surprised” by the escape, and expressed some confidence that El Chapo could be recaptured, saying that “we learned a lot about his evasive tactics,” the last time around.

One key piece of information authorities learned during the last search for the drug kingpin, whose nickname means “The Short One” or “Shorty” in Spanish, was that he had a fascination with airplanes, and couldn’t stay away from flying even though he was a “white-knuckle” flier.

The source suspects that El Chapo will try to stay under the radar as much as possible in the coming days and weeks.

“My guess is he will go dark, travel very light for speed, and head to the safety of the Sinaloa mountains as soon as possible,” the source told ABC News.