Researchers have long recognized that Jack Ruby's stalking and murder of Oswald is clear evidence that JFK was killed by a conspiracy. Researchers have also long recognized that the WC's version of Ruby's motives and actions is not only wrong but downright silly.
The WC dismissed key evidence that proved Ruby's action was not a spontaneous act of grief but a carefully planned execution. Around 3:00 PM on Saturday, 11/23, Ruby returned to the Allright Parking Garage and again telephoned KLIF radio
to try to find out when Oswald would be transferred. Garnett Hallmark, who worked at the garage, was standing next to Ruby while Ruby was on the phone. Hallmark heard Ruby's end of the conversation. Hallmark told the WC that after Ruby mentioned that the transfer might be delayed, he said, “I understand they are moving Oswald over to the county jail" and "
you know I'll be there.”
So Ruby was not at the DPD building by chance just before Oswald was supposed to be transferred. He was there because he planned to be there.
However, Ruby's plan was to try to make his silencing of Oswald appear to be an unplanned, spontaneous act based on his supposed grief over JFK's death and his alleged concern for Jackie. That's why he sent a Western Union wire transfer to one of his employees minutes before he entered the DPD basement, when he could have just as easily given her the money in person the next day. That's why he left his two dogs in his car (along with thousands of dollars in cash).
But Hallmark's testimony alone destroys this tale. The day before the Oswald transfer, Ruby was on the phone trying to find out when the transfer would occur, and once he thought he knew, he said, "I'll be there."
Hallmark also testified at Ruby's trial, and Hallmark's testimony was crucial in proving that Ruby did not act spontaneously but that he stalked Oswald and planned his silencing of Oswald in advance.
Another big hole in Ruby's story was his claim that he was never at Parkland Hospital on the day of the assassination. Seth Kantor, a respected journalist who knew Ruby well, saw and spoke with Ruby at Parkland soon after the shooting. Incredibly, the WC chose to believe Ruby over Kantor.
Here's a good article by John Armstrong about Ruby:
https://harveyandlee.net/Ruby/Ruby.html