Seconds after Secret Service agent Jerry Parr wrestled Ronald Reagan into the presidential limousine outside the Washington Hilton on March 30, 1981, he had to make a critical decision: Should the car rush them back to the White House, or to George Washington University Hospital, just a few blocks away?
The 50-year-old agent did not know how badly Reagan was hurt, or exactly what crisis was on his hands. What he did know was that a deranged gunman had begun firing at very close range outside the hotel on that grim, gray day, 70 days into Ronald Reagan’s...