WASHINGTON - Bill Tighe, chief of staff for U.S. Rep. Tom Marino, said he spoke to press secretary Ryan Shucard following his arrest on a gun possession charge and was told he made "a terrible mistake."

After less than two months in his new job, Shucard was arrested Friday for trying to bring a gun into the congressional office building where he works.

He was arrested about 9:15 a.m. as he tried to enter the southeast doors of the Cannon Office Building, according to Capitol Police. Police found him in possession of a Smith & Wesson 9mm handgun and a magazine of ammunition. Capitol Police charged him with carrying a pistol without a license, a felony that carries a penalty of up to five years in prison. They declined to elaborate further on the incident or the charge.

Police found the gun during a routine search required for entry into the building. Everyone entering a congressional office building must pass through a metal detector. Bags and other belongings are passed through an X-ray scanner.

Marino's office is at 410 Cannon Office Building.

Tighe said Shucard, who started his job May 27, was immediately placed on unpaid leave. Shucard's salary is $52,000 a year.

"He's a firearms owner in Virginia. He forgot that he had it with him," Tighe said.

Capitol Police told him they do not believe Shucard brought the gun to work with him to harm anyone, Tighe said.

He emphasized that Marino, even though he favors a person's right to carry a gun, was upset at Shucard.

"Tom is pro-Second Amendment and we are deeply, deeply disappointed," Tighe said. "This shows a lack of judgment and a real disregard and knowledge of firearm laws. It's irresponsible."

Shucard came to Marino after nine months as media relations manager for the American Society of Pension Professionals & Actuaries, according to Shucard's LinkedIn page.

A native of Littleton, Colo., he is a 2006 graduate of Columbine High School and earned bachelor's degrees in political science and government and journalism in 2011 from the University of Northern Colorado. He worked for almost 18 months as aide to U.S. Sen. Joseph Lieberman, then seven months at DDC Advocacy in a Maryland suburb of Washington before joining Marino's office.

In March 2007, an aide to U.S. Sen. James Webb of Virginia was arrested for trying to bring a loaded gun into the Russell Senate Office Building. A federal prosecutor dropped the charge a month later, saying he could not prove the charge beyond a reasonable doubt.