CNN  — 

The man accused of crashing a U-Haul truck into a security barrier near the White House Monday night praised Adolf Hitler to investigators after his arrest and said that he aimed to “kill the President” if necessary to overthrow the government and install himself in power, according to court documents.

Sai Varshith Kandula, 19, of Chesterfield, Missouri, is in custody and has been charged in federal court with one count of depredation of property of the United States in excess of $1,000. US Park Police originally arrested Kandula on several charges, including threatening to kill or harm a president, vice president or family member. It’s possible that prosecutors add additional charges as the case progresses.

Kandula, in handcuffs and wearing a t-shirt and shorts, appeared in DC Superior Court Tuesday afternoon, US Park Police told CNN, and was held in custody without bail. He has not yet entered a formal plea in federal court – where his case is expected to continue with an initial appearance on the single charge Wednesday – and a lawyer for him in that case has not yet been named publicly.

The Secret Service said no agency or White House personnel were injured in the incident.

The truck, which carried a Nazi flag among other items, crashed into security barriers on the north side of Lafayette Square at 16th Street just before 10 p.m. ET, the US Secret Service said. A preliminary investigation revealed the driver may have intentionally struck the barrier, the agency later said.

Kandula made threatening comments regarding the White House at the scene, including that he wanted to kidnap and harm President Joe Biden, law enforcement sources told CNN. Authorities are considering the role mental health may have played in this incident, one source said.

In court documents unsealed Tuesday, investigators said that a US Park Police officer saw Kandula drive up onto the sidewalk and into metal barriers, sending several pedestrians running. When the truck failed to go through the barriers, Kandula allegedly backed up before striking the barriers a second time.

After the crash, Kandula allegedly removed the flag “from a black backpack he was carrying.”

In an interview after the arrest, investigators asked Kandula about the Nazi flag he displayed after the crash. The 19-year-old said he bought the flag because “Nazi’s have a great history,” adding that he admires their “authoritarian nature, Eugenics, and their one world order,” according to court documents. Investigators wrote that “when asked if he looks up to any leaders, Kandula answered ‘Hitler, because he was a strong leader.’”

Kandula told officers that he had been planning the attack for six months and had flown to Washington from St. Louis earlier that evening, according to court documents.

Prosecutors said Kandula also told officers that he aimed to “get to the White House, seize power, and be put in charge of the nation,” and was prepared to “kill the President if that’s what I have to do and would hurt anyone that would stand in my way.”

The White House said Biden was not in danger during the incident. National Security Council Coordinator for Strategic Communications John Kirby told CNN’s Kate Bolduan that it was “difficult to know for sure” what the suspect’s motivations were and that the incident was still being investigated.

Video taken by a witness showed the 26-foot moving truck stopped on the sidewalk near Lafayette Square before the driver accelerates and crashes into a set of security bollards that ring the White House complex to prevent unauthorized vehicular traffic.

After the crash, the truck was searched by bomb technicians and no explosives or incendiary devices were found, a law enforcement source familiar with the investigation told CNN.

Video from CNN affiliate WUSA shows a remotely operated police robot approaching the rear of the truck and lifting the cargo door, followed by an FBI bomb technician who inspected the vehicle. A Park Police officer was later seen taking inventory of the U-Haul truck, packing up several pieces of evidence.

The incident prompted road closures as authorities investigated the crash, and the nearby Hay-Adams hotel was evacuated at the request of the Secret Service, a hotel employee told CNN. The hotel guests and employees were allowed back in when police deemed it safe a short time later.

The FBI’s National Capital Response Squad is assisting Park Police and the Secret Service in the investigation.

Agents from the US Secret Service and the FBI’s Joint Terrorism Task Force Tuesday executed a federal search warrant at Kandula’s Missouri home, according to a federal law enforcement official. They searched for notes, computers or any evidence of planning that led up to or motive behind Monday’s events.

Former high school classmates of Kandula described him as quiet and someone who didn’t get into trouble.

Errion Barfield, a former classmate of Kandula’s at Marquette High School, described him as a “good dude” who “never got in trouble” and “never made a scene in school.”

This headline and story have been updated with additional developments.

CNN’s John Miller, Evan Perez and Curt Devine contributed to this report.