As thousands of tourists packed the National Mall this weekend, Ty Carroll Mitchum parked his vehicle on Capitol Hill Sunday, drawing suspicion as he wandered around the U.S. Capitol grounds muttering to himself.

His behavior caught the attention U.S. Capitol Police, who discovered three unregistered firearms and more than 100 rounds of ammunition in his vehicle.

According to the charging document, Mitchum possessed a Remington 12 Gauge Shotgun Model 870, a Springfield Armory 9MM handgun Model DX9, and a Smith and Wesson 38 caliber revolver. He also had 69 rounds of 9mm ammunition, as well as 38 rounds of 44 caliber bullets. It's unclear whether any of the firearms were loaded.

Sources say Mitchum did not threaten anyone with the firearms and law enforcement officials downplayed the incident, pointing to other routine stops this year that have yielded unregistered firearms near the Capitol.

But with the spotlight on Congress this week as it begins debating new gun control measures, this arrest seems to stand out among the routine incidents.

According to the charging document, at 12:45 p.m. Sunday, officers spotted a possible suspicious individual moving toward a restricted area on the Senate side of the Lower West Terrance of the U.S. Capitol. Officers moved in to investigate and Mitchum, was observed returning to the area apparently talking to himself.

Two officers approached the suspect, who said that he had driven to Washington, D.C., from Clearwater, Fla., to speak with his lawyer, who he identified as John Morgan, in reference to his role in helping take down Osama Bin Laden's terror network. A name check was conducted on Mitchum, but returned with no wants or warrants.

Then the suspect informed the officers that he had two firearms in his vehicle for "protection," and he willingly handed his keys over to an officer, stating; "You can go check." He was found to have no weapons on his person.

Mitchum told officers that someone may have placed an Improved Explosive Device on or in his vehicle. His vehicle was then searched, and the firearms and ammunition were discovered. Mitchum was arrested and transported to USCP Headquarters for processing.

"[It's] hard to know what is in someone's head but I am certainly pleased that our officers were able to make an arrest and recover these weapons before something may have occurred," U.S. Capitol Police Chief Kim Dine wrote in an email.

Mitchum, 59, was charged with three counts of unregistered firearms and another count of unlawful possession of ammunition - all misdemeanors. He is still in custody today, undergoing a 24-hour forensic evaluation while he awaits a Mental Observation hearing at 2:00 p.m. Tuesday in DC Superior Court.

His case is being handled by the DC Attorney General's office with Magistrate Judge Michael McCarthy at DC Superior Court presiding. Mitchum was assigned a court-appointed attorney, Chidi Ogolo, who did not immediately return messages Monday.