Judge Andrew Napolitano reacted to new revelations and a formal change in the timeline of events the night of the Las Vegas massacre.
Law enforcement said Mandalay Bay security guard Jesus Campos was engaged by murderer Stephen Paddock six minutes before Paddock turned his gun on concertgoers.
Campos was shot during that time, while Paddock unloaded 200 rounds in the guard's direction.
"The news is not that he was shot," Napolitano said.
Napolitano said that, at that point, Mandalay Bay "knew of the existence and presence of automatic[-type] weapons six minutes before he started killing people."
Campos likely had a radio, and the casino is rife with security cameras in the hallways and on the gaming floor, Napolitano said.
He added that the casino and its parent company, Metro-Goldwyn-Mayer, should be prepared to be the "principal target" for lawsuits regarding failure to stop or inhibit Paddock's actions.
"I tip my hat to the police, particularly Sheriff [Joseph] Lombardo... I do not tip my hat to the hotel," Napolitano said.
"[Campos being wounded and shot at 200 times] should've triggered an enormous response long before he started the killing," he said.
"What was the security guard's training?" he asked. "What did they learn, when did they learn it and what did they do about what they learned?" he asked.