The couple suspected in Sunday’s Las Vegas shopping center shooting tried to join the armed standoff against federal agents at Cliven Bundy's Nevada ranch in April, but they were asked to leave for being "too radical," Bundy's son said.
Jerad and Amanda Miller did not "align themselves" with the April protest’s main issues, Ammon Bundy told The Associated Press.
"Not very many people were asked to leave," he said. "I think they may have been the only ones."
Cliven Bundy, 67, has been engaged in a 20-year legal fight over cattle-grazing on federal land. The patriarch of a large Mormon family, Bundy became a conservative folk hero of sorts because of his standoff with the government, but he later drew criticism for his comments that black people were “better off as slaves, picking cotton.”
WATCH: Deadly Shooting Spree in Las Vegas
Jerad Miller was interviewed by the media at the ranch protests, sharing his anti-government views.
"I feel sorry for any federal agents that want to come in here and try to push us around," he told NBC affiliate KRNV-TV.
That interview came two months before Miller and his wife reportedly ambushed two police officers Sunday, shooting them at point-blank range inside a Las Vegas pizza buffet.
Investigators say they draped the officers' bodies with a "Don't Tread on Me" flag, pinned a swastika on them and a note that read "The revolution has begun."
Second Assistant Sheriff Kevin McMahill said the couple's hatred fueled the attack.
"They equate government and law enforcement with fascism and with those who supported the Nazis," McMahill said.
The Millers later allegedly killed an armed civilian inside a nearby Walmart. Joseph Wilcox tried to stop their rampage, but was gunned down.
"I'm proud of him, I really am," Wilcox's sister CJ Foster said. "I just wish he hadn't done it."
When cornered by officers, Amanda Miller shot her husband several times and then herself.
A friend of the couple's, Kelley Fielder, was distraught Monday, convinced she could have done something to stop the attack. Amanda Miller cryptically told her "If I die … I die," the morning of the rampage, Fielder said.
"I got five deaths on my shoulders," Fielder said, crying. "I should have called the cops."
The Associated Press contributed to this report.