After having been charged with both the murder of Dallas police officer J.D. Tippit and President John F. Kennedy, Lee Harvey Oswald was to be moved from the Dallas police headquarters to the more secure Dallas County Jail.
With threats having already been received against Oswald, officials made the determination to move Oswald during the morning of Nov. 25, instead of the previous evening. Additionally, police decided it was best to transport Oswald in an armored car after both the Federal Bureau of Investigation and Dallas County Sheriff's Department received calls from someone claiming that a committee had decided "to kill the man that killed the president."
The plan was to lead Oswald through the basement and to the truck, where the driver would then be instructed as to the route to take to the Dallas County Jail. while the press knew the approximate time of the prisoner transfer, they were not made aware of the details of the route to be taken.
Ahead of moving Oswald through the basement, officials staged officers at the garage entrance and thoroughly searched the cleared basement, including the rafters, air conditioning ducts, closets, automobile trunks and elevators, for anyone who shouldn't be present.
With the search completed, police allowed members of the media to enter the basement and gather along the entrance to witness the prisoner transfer.
The armored truck that was to ferry Oswald to the county jail remained parked at the top of the garage's exit ramp because there was concern over the clearance and the truck's ability to make it up the incline without stalling.
When Oswald arrived at the basement jail office, there were estimated to be as many as 50 members of the media and 75 police officers assembled in the area.
As Oswald's entourage led him into the basement and toward the armored vehicle, someone shouted "Here he comes!" Spotlights suddenly illuminated, flashbulbs popped and the crowd of police and media surged forward.
"After Oswald had moved about 10 feet from the door of the jail office, Jack Ruby passed between a newsman and a detective at the edge of the straining crowd on the Main Street ramp. With his right hand extended and holding a .38 caliber revolver, Ruby stepped quickly forward and fired a single fatal bullet into Oswald's abdomen," according to the Warren Commission Report.
At 11:21 a.m., in the presence of more than 125 people, including 75 police officers, the man accused of murdering the President of the United States had been shot on live television by a Dallas businessman who should have never been present at the prisoner transfer.
After the gunshot, it was total pandemonium in the basement. Officers pounced on Ruby as Oswald collapsed to the ground.
An ambulance soon replaced the armored car in the basement and Oswald was rushed to the emergency room at Parkland Hospital.
Oswald was wheeled into Trauma Room 2, the same room where Gov. John Connally was treated after the shooting in Dealey Plaza. At 1:07 p.m., Oswald was pronounced dead across the hall from where doctors tried unsuccessfully to save the life of President Kennedy just two days before.
Meanwhile, Ruby was arrested and eventually charged with Oswald's slaying. He would eventually be found guilty and sentenced to death, though he died in prison of lung cancer while awaiting a date for an appeal.
Ruby's shooting of Oswald fueled speculation of a conspiracy to murder the president and then silence his assassin, or the person framed as the assassin. The Warren Commission would later determine that Ruby slipped into the basement unaided, most likely via the ramp along Main Street, just three minutes before he shot Oswald.
The investigation into JFK's murder by the Warren Commission determined that both men, Oswald and Ruby, acted alone.
†Source: Warren Commission Report