"In my view, the Secret Service lost before it even started that motorcade," says Dan Emmett, who became a special agent in 1983, 20 years after the assassination. He recounts his experiences on the presidential detail in his 2012 book, "Within Arm's Length."
The president was sitting in an open-top limousine with the windows down. The route his parade would follow had been printed in local newspapers days prior. And footage of the motorcade moments before the shooting showed people running up to the cars and trying to shake hands with the high-profile passengers.
"Today that is absolutely impossible. That isn't going to happen," says Emmett.
Many of his initial instructors kept the lessons from that incident at the forefront of their training. Secret Service protocols now are founded on what failed that day.
IMPROVING THE SECRET SERVICE
The 1964 report from the Warren Commission takes aim squarely at improvements to the Secret Service, among its many findings in the wake of the Kennedy assassination.
"Consistent with their high responsibilities, presidents can never be protected from every potential threat," the report states in its initial summary and conclusions. Its subsequent recommendations provide the roadmap that has wholly altered the size and scope of the Secret Service mission.
It begins with increasing the size of its agent corps and facilities, immediately followed by the need for infrastructure to anticipate danger beyond direct and immediate threats to the president.
"In effect, the Secret Service largely relied upon other Federal or State agencies to supply the information necessary for it to fulfill its preventive responsibilities," the report states. That needed to change.
The findings include improvements to security around the presidential motorcade and always having the president's physician present. It also advocates granting more authority to the organization to take on and oversee all aspects of keeping the president safe as he travels through various state and federal law enforcement jurisdictions.
"The Secret Service learns and studies all incidents and potential incidents to improve how we do protection," says Brian Leary, a Secret Service spokesman, outlining one of the key attitude shifts that has defined the organization over the last 50 years. "The way the Secret Service does protection is based on 'protective advances.'"
"When the president goes anywhere, it doesn't matter where it is, an advance is done," says Emmett, who retired after 21 years with the Secret Service, including stints on the protective details for Presidents George H.W. Bush, Bill Clinton and George W. Bush.
The president can't take a walk from the White House across 15th Street to the National Press Club, for example, without a series of agents heading there first. They perform seemingly simple duties, such as scouting the location of bathrooms and holding rooms to ensure the president's movements do not get hampered by an unexpected blockage. These teams cover every inch of the president's planned itinerary all the way up to establishing counter-sniper and counter-assault posts.
Even seemingly impromptu movements, such as the president exiting his armored limousine during an inauguration parade to walk down Pennsylvania Avenue, are closely coordinated with his bodyguards who go to great lengths to eliminate surprises.
This also requires close coordination with the president's staff. The Warren Commission and subsequent security experts cite Kennedy's insistence on appearing close with this electorate. He demanded the removal of his limousine's drop-top that day in Dallas, and a parade route that gave him greater public access.
Much of the Secret Service's approach now lies in the close relationships its agents form with the president's inner circle, ensuring cooperation regarding his safety while allowing him to perform the responsibilities of the public office.
However, the president is not paid to stay inside the protective enclave of northwest Washington, D.C. As the Warren Commission notes in its initial section on the Secret Service, "The Commission recognizes that the varied responsibilities of the President require that he make frequent trips to all parts of the United States and abroad."
Corrected on : Corrected, 11/19/13: An earlier version of this article misidentified Jeffrey Engel, a professor at Southern Methodist University.