A man was arrested outside of a campaign rally for former President Donald Trump in Southern California, and multiple guns were illegally in his possession, according to authorities. The arrest took place at a checkpoint at the intersection of Avenue 52 and Celebration Drive in Coachella at 4:59 p.m. on Saturday, the Riverside County Sheriff's Office said. The rally was scheduled to start at 5 p.m., but Sheriff Chad Bianco said at a news conference Sunday that the arrest took place before Trump arrived. The driver of a black SUV, who was later identified as 49-year-old Vem Miller of Las Vegas, was found to be in illegal possession of a shotgun, a loaded handgun, and a high-capacity magazine. Miller was then taken into custody and booked at the John J. Benoit Detention Center on suspicion of possession of a loaded firearm and possession of a high-capacity magazine. The Sheriff's Office said the incident had no impact on the safety of rally attendees or former President Trump. According to the Riverside County Inmate Information System, Miller was released from the detention center Sunday on $5,000 bail. Deputies became suspicious of Miller due to the interior of his vehicle being in "disarray" and having fake license plates consistent of groups claiming to be "sovereign citizens," Bianco said Sunday. Miller claimed to be a journalist, and had multiple fake passports with different names inside, Bianco said. The vehicle was unregistered, Bianco said. Bianco told reporters on Sunday that any charges coming from Riverside County would be limited to the firearm-related charges. If any further charges were to be filed, they would likely come federally. No additional details were immediately made available. Republican presidential nominee former President Donald Trump arrives to speak at a campaign rally at the Calhoun Ranch, Saturday, Oct. 12, 2024, in Coachella, Calif. (AP Photo/Alex Brandon) Officials didn't say where the guns were located in his SUV at the time of the arrest. On Sunday morning, Bianco, an open supporter of Trump, said the incident was "probably" a third assassination attempt on the former President, according to the Southern California News Group. Bianco told the news organization that Miller presented fake VIP and press passes at the checkpoint, which is what led to the search. “We probably stopped another assassination attempt," Bianco told SCNG. At the news conference on Sunday, Bianco spoke in less clear terms about what he believed Miller's intent to be. He told reporters that he "didn't remember" calling the incident a possible assassination attempt to the SCNG, but admitted that it was something that he "would say." "No matter what, it's all going to be speculation about what his intentions were getting there," Bianco said. "If you're asking me right now, I probably did have deputies that prevented the third assassination attempt." "The presence that we had at the rally ... I am glad we're not talking about this after we shot [Miller]," Bianco continued. In a statement released Sunday by the Department of Justice, officials said: "The U.S. Attorney's Office, U.S. Secret Service, and the FBI are aware of the Riverside County Sheriff's Office arrest on Saturday. The U.S. Secret Service assesses that the incident did not impact protective operations and former President Trump was not in any danger. While no federal arrest has been made at this time, the investigation is ongoing. The U.S. Attorney's Office, and FBI extend their gratitude to the deputies and local partners who helped ensure the safety of last night's events." Miller is a registered Republican. He filed to run for Nevada's state assembly in 2022. As of Sunday afternoon, Trump hadn't publicly commented on the incident. The arrest comes as multiple high-profile attempts of violence against the former President have taken place during the heated election cycle. FILE - Republican presidential candidate former President Donald Trump is surrounded by U.S. Secret Service agents at a campaign rally, Saturday, July 13, 2024, in Butler, Pa. (AP Photo/Evan Vucci, File) On July 13, Trump was grazed in the ear by a bullet coming from the gun of 20-year-old Thomas Matthew Crooks. Crooks was shot and killed by a member of the Secret Service. Ryan Wesley Routh, 58, is currently being prosecuted on gun charges after he hid out near a Florida golf course in an alleged attempt to have a clean shot at the former President and current Republican presidential nominee on Sept. 15. Sofia Pop Perez contributed to this report.