DENVER —  New York Police Department has been planning its strategy to protect Pope Francis for his visit this week.

According to police Commissioner Bill Bratton, an interesting detail is that authorities have been studying the pope’s body language to keep him safe.

“We plan for the worst or the unexpected. We watched very closely all of his appearances around the world, how he interacts with the crowds,” Bratton said.

Many can only imagine what it’s like to be in the NYPD commissioner’s shoes, but one retired Denver police commander doesn’t have to imagine. He lived it.

When Pope John Paul II visited Denver 22 years ago, it was Mike O’Neill Sr.’s  task to protect him.

O’Neill was the venue commander at Mile High Stadium, where more than 100,000 pilgrims gathered for World Youth Day.

“We had initially planned to put an officer or cadet about every 50 feet or so,” O’Neill said.

In the end, he said there was not a single incident.

O’Neill said Pope Francis’ trip is a little different, especially after 9/11, but looking back, he can hope history repeats itself.

“It was the highlight of my 37 years with the Denver Police Department. One of the highlights of my life, being in the presence of a pope who eventually became a saint,” he said.