A man who illegally possessed a shotgun and a loaded handgun was arrested Saturday at an intersection near Donald Trump's rally in Coachella, California, police said.

The 49-year-old suspect, Vem Miller, was driving a black SUV when he was stopped at a security checkpoint by officers who found two firearms and a “high-capacity magazine.”

Mr. Miller was then taken into custody “without incident,” the Riverside County Sheriff's Office said, and charges of possession of a loaded firearm and possession of a high-capacity magazine were filed.

The U.S. Secret Service said Trump was “in no danger,” adding that the incident had no impact on protective measures.

A local sheriff called the suspect a “lunatic” and his office added that the encounter did not compromise the safety of Trump or those attending the rally.

Many questions remain unanswered.

While Riverside County Sheriff Chad Bianco said it was impossible to speculate about what was going on in the suspect's mind, he said he was “truly confident” that his officers prevented a third assassination attempt.

He added that it may be impossible to prove that this was the man's intention.

A federal law enforcement official told CBS News there was no evidence of an assassination attempt in connection with this incident.

Federal authorities say they are still investigating the incident and that it would be their responsibility to file additional charges.

Mr. Bianco is an elected official and Republican who has previously expressed support for Trump. He also serves as a surrogate for Trump's re-election campaign.

The incident – which occurred at 4:59 p.m. PDT (00:59 GMT) – an hour before Trump was scheduled to appear on stage – underscores once again the intense security measures surrounding him and the dangers the former president faces leading up to the election there are still over three weeks left.

It follows two high-profile alleged assassination attempts on Trump earlier this year.

Mr Miller was charged with two weapons offenses and released on $5,000 (£3,826) bail. No federal charges were filed.

In a police press conference earlier on Sunday, Mr. Bianco warned that he might not be able to “give all the information … because of what we are doing.”

The sheriff added that as the suspect approached an outdoor area near the rally site, he “gave every indication that he was allowed to be there.”

But when the suspect reached the interior, “a lot of irregularities came to light,” Sheriff Bianco added, explaining that the vehicle had a fake license plate and was “in disarray” inside.

Multiple passports with multiple names and multiple driver's licenses were found in the car, the sheriff said, adding that the license plate was “homemade” and unregistered.

He added that the suspect told authorities he was a member of the far-right group called Sovereign Citizens.

He said the license plate was also “indicative of a group of individuals who claim to be sovereign citizens,” but he did not conclude that Mr. Miller was a member.

“I wouldn’t say it’s a militant group. It’s simply a group that doesn’t believe in government and government control,” he said. “They don’t believe the government and laws apply to them.”

According to a statement from federal authorities, the U.S. Attorney's Office, the Secret Service and the FBI are aware of the arrest.

“The U.S. Secret Service believes the incident had no impact on protective measures and that former President Trump was not in danger,” the statement said.

“Although there has been no federal arrest at this time, the investigation remains ongoing. The U.S. Attorney’s Office, the U.S. Secret Service and the FBI thank the deputies and local partners who helped ensure the safety of last night’s events.”

Security around Trump has been significantly increased in the wake of previous suspected assassination attempts.

On the Saturday before Mr. Miller's arrest, Mr. Trump held his second rally this year in Butler, Pennsylvania, at the same spot where his ear bled after a sniper fired several shots in his direction, hitting a person in the crowd killed.

Another man is currently in jail after being arrested outside the Trump International Golf Club in West Palm Beach in September. The man was seen hiding in bushes near the golf course with the muzzle of a rifle poking through the bushes.