The dramatic improvement in survival raises a question. Could today's doctors and techniques have saved King or Kennedy?
For Martin Luther King, the answer is no.
King, 39, was struck by a rifle bullet that exploded through his right jaw and neck, severing his spinal cord. A medical examiner ruled that death was almost instantaneous, and no one disputes that finding today.
"He was dead on impact," said Denise McFall, spokeswoman for the Martin Luther King Jr. Center for Nonviolent Social Change in Atlanta.
But for Bobby Kennedy, the circumstances are vastly different.
Kennedy, 42, was shot in the kitchen of the Ambassador Hotel in Los Angeles. The .22-caliber bullet tore into his head behind his right ear just at the hairline.
In the moments after the shooting, Kennedy was conscious and capable of some movement. He asked his wife, Ethel, "Am I all right?" He was handed a rosary, which he pulled to his chest.
He was transferred from the hotel to one hospital and then a second, where he underwent surgery three hours after the shooting. He lived for 25 hours.
Trauma treatment has changed so dramatically that almost everything that happened to Kennedy would be done differently today.
In 1968, emergency treatment was just evolving into a coordinated system. Physicians returning from Vietnam had seen how corpsmen saved lives through rapid transportation and treatment of the seriously wounded and suggested a similar system, a trauma center, be set up.
"Today a trauma patient gets an immediate response from a trauma team," said Dr. Juan Asensio, the chief of Hahnemann University's division of trauma surgery. "The patient doesn't wait for us to get ready."
The response begins today with a call to 911. Within minutes, a rescue unit staffed by paramedics or emergency medical technicians arrives.
When Kennedy was shot, pandemonium erupted. Ten minutes elapsed before an ambulance driver and orderly arrived.
One attendant took Kennedy's shoulders and the other grabbed his ankles as they hoisted his body onto a stretcher.
"They didn't have paramedics then. They just used some strong guys who could haul the body around," said Asensio.
In the ambulance, Kennedy appeared to be gasping for air. Only then did the attendant slip an oxygen mask on him.
He was taken to Central Receiving Hospital, where a breathing tube was put into his trachea. Doctors determined that he needed surgery and would have to be transferred. By the time Kennedy was taken to the Hospital of the Good Samaritan, known as Good Sam, nearly 60 minutes had elapsed.
"Today, the paramedics would insert a tube into the trach at the hotel when they'd see it was a brain injury," said Dr. Michael McMonigal, of the University of Pennsylvania Medical Center "It makes a big difference.
"Today, they'd put a rigid collar on the neck. They didn't have them then. There wasn't that much concern about the neck flopping.
"Today, they don't take a person to the nearest hospital. A trauma patient is taken to the nearest trauma center."
Trauma treatment defines itself by the Golden Hour. The first 60 minutes after an injury are the minutes when a life can be saved.
"Time is the magic number. You have one hour to provide definitive care," said McGonigal. "After that, deaths mount."
At a trauma center today, a person with a gunshot wound to the head would automatically be taken for a CAT (computerized axial tomography) or CT scan. This diagnostic technique, which came into use in 1972, produces accurate cross-sectional images of the brain (or whatever tissue is being evaluated) within 10 minutes.
When Kennedy arrived at Good Sam, doctors took X-rays of his skull, spine and chest. Then they went to the radiology department to review the films and see what damage the bullet had done. They concurred on the necessity of surgery. Three hours had passed since the shooting.
"The CT can help you decide whether someone will survive," said Dr. Christopher Getch, Temple University Hospital's chief neurosurgery resident. ''It tells you whether someone should be put through an operation."
The goals of surgery, Getch said, haven't changed since 1968: clean up accessible bone or bullet fragments, repair any tears and prevent infection.
Dr. Maxwell M. Andler, one of three neurosurgeons who operated on Kennedy, recalled earlier this month what happened. It was his first interview since the assassination.
"Ordinarily, if a patient was maintaining his own position and breathing on his own, you'd leave him alone," said Andler. "You can only do damage by stirring things up. But Sen. Kennedy was deteriorating rapidly."
That Kennedy was speaking after having been shot was a major reason for surgery. "You must do anything in extremis, even if there's a five to 10 percent chance of helping. You can't do much worse than what's happening," said Andler.
Now, following surgery, patients receive aggressive drug therapy to minimize brain swelling, which can lead to death. Sometimes, the patient may live but never recover, breathing but never waking.
Kennedy received some drugs to prevent brain swelling, but his injuries were too severe. By late afternoon, his brainwaves were flat. He was brain dead.
"Today, he'd be the ideal organ donor for liver, lungs, cornea, kidney, all sorts of things. He had a strong, strong heart," said Andler. "He was a tough, wiry man."
For another seven hours, a respirator kept Kennedy's lungs breathing until Ethel Kennedy agreed to turn off the machine. Then his heart stopped beating.
Andler said it is "extremely doubtful" that today's medicine could have saved Kennedy.
"There are certain areas of the brain that you just can't repair," said Andler. "You've got vital, controlling tissue in the brain stem. If it's destroyed, you can't replace it. No mechanism, no technique, there's nothing you can do to replace what's lost."