LAS VEGAS — A husband and wife who went on a deadly shooting rampage in Las Vegas harbored anti-government beliefs and left a swastika and a “Don’t tread on me” flag on the body of one of the two police officers they killed, authorities said Monday.

Jerad and Amanda Miller had been kicked off a Nevada ranch where anti-government protesters faced down federal agents earlier this year because they were “very radical,” according to the son of rancher Cliven Bundy.

Assistant Sheriff Kevin McMahill said the Millers had ideology shared by “militia and white supremacists,” including the belief that law enforcement was the “oppressor.”

Police believe the shootings were an isolated act, not part of a broader conspiracy to target law enforcement, McMahill said.

Ammon Bundy, one of Cliven Bundy’s sons, said by telephone that the Millers were at his father’s ranch for a few days this spring before they were asked to leave by militia members for unspecified “conduct” problems. He called the couple “very radical” and said they “did not align themselves” with the beliefs of other protesters, who thwarted a roundup of Cliven Bundy’s cattle by the U.S. Bureau of Land Management, which wants to collect more than $1 million in grazing fees and penalties.

While thousands of people have been to the site over the last couple of months, “Not very many people were asked to leave. I think they may have been the only ones,” Ammon Bundy said.

On Sunday, the two Las Vegas police officers were having lunch at a pizza buffet in an aging strip mall about 5 miles northeast of the Las Vegas Strip when the Millers fatally shot them.