STERLING, Va. - Following an FBI raid of a Virginia home on Friday, new court documents show FBI investigators suspected the man living at the Loudoun County home of supporting ISIS and researching how to conduct an attack.
The suspect is Sean Andrew Duncan, a U.S. citizen from Pittsburgh, Pennsylvania who had moved to Sterling, Virginia in June 2017.
A relative of Duncan's reportedly told investigators that he had had "converted to Islam, may have been radicalized, and voiced his approval of westerners being beheaded in the Middle East."
Documents described how FBI investigators were able to track down Duncan through social media as well as encrypted message programs and apps.
They say Duncan had been using the Twitter handle "@DawlahtullIslaam" which "roughly translates to 'The Islamic State.'"
Investigators also describe Duncan's plans to travel to Turkey with his wife and make their way into Bangladesh. The two were denied entry to Turkey in February 2016, deported to the U.S. and questioned by the FBI upon return.
They say the phone also contained photos of machete knives. There were also searches for the "Black Flag" of ISIS and various assault rifles.
The FBI says the searches are "indicative of an individual planning and researching how to conduct an attack and defend himself from bodily harm."
The FBI got more information on Duncan from a woman in custody of international authorities for actively planning to join ISIS, as well as a known ISIS recruiter, and an undercover FBI employee.
Documents show a search was authorized for Duncan's home in Sterling on December 19, and was executed on December 29 by FBI agents.
Investigators say moments before entering the residence, Duncan ran barefoot from the home through the back door. When FBI Agents yelled at him to stop, Duncan threw a plastic baggie overhead, which was later found to contain a memory chip inside a thumb drive that was broken into pieces, found in liquid with frothy white bubbles.
FBI investigators believe the thumb drive was destroyed in order to impede and obstruct the FBI's investigation.
Agents along with members of the Loudoun County Sheriff's Office and Virginia State Police were seen investigating Duncan's home on Friday.
FOX 5's Cori Coffin reports multiple boxes were seen piling up inside the home and several law enforcement members were seen bringing items and boxes from the home. There was also a mobile unit stationed in the area with FBI agents inside.
This is a developing story. Stay with FOX 5 for updates.