BALTIMORE -- A man drove through a perimeter gate at Baltimore/Washington International Thurgood Marshall Airport Saturday afternoon and made it onto a plane with a backpack before authorities could catch up with him and detain him, reports The Baltimore Sun, a media partner of CBS Baltimore.

The newspaper cites Maryland Transportation Authority Police.

"He did enter an unoccupied aircraft," MDTA Police spokesman Kevin Ayd tells The Sun. "The aircraft and the backpack were checked, and there was nothing that was alarming."

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The backpack contained only "papers and personal effects," and the FBI determined "this was not terrorism-related," Ayd said.

The FBI didn't respond to a request for comment Monday, The Sun reports.

MDTA police responded and took Andrew John Kottke, 42, from Laurel, Maryland into custody.

The U.S. Marshals Service confirms to CBS Baltimore that Kottke was a deputy U.S. Marshal until he recently resigned.

BWI flight operations weren't impacted by the incident.

Police don't yet have a motive.

Court records show just hours before the incident at BWI, a domestic violence case was brought against Kottke in Prince George's County.

CBS Baltimore has also learned Kottke is an accomplished officer. He once received an Officer of the Month award as a Deputy U.S. Marshal.

"This is still a very active investigation at this time. So we don't really have much more information to go on, as the investigators go into the reason the individual did drive through the security gate," Kevin Ayd says.

One aviation expert says the incident may have exposed a major security vulnerability.

"There's some real red flags by this event," Keith Franz tells CBS Baltimore.

He says despite various layers of security at BWI and all airports, they clearly aren't without some flaws.

"Bottom line is this a serious wake up call? There's no question we've got to get this straight. This cannot happen again."

Ayd tells The Sun the plane was a smaller model aircraft, such as those that are boarded via stairs on the tarmac. He also says he didn't know who the owner of the plane is or whether it is from a major airline.

Ayd says the incident occurred around 1:30 p.m., when a vehicle broke through the perimeter gate at the Signature Flight Support, which is mostly used for private and charter planes.

Within hours, the hole in the fence was replaced by concrete barriers, security and police officers.

Police haven't announced the charges Kottke is facing.