Jonathan Wienke, 35, an analyst in the office of intelligence and analysis and military veteran, was arrested on June 9 at the Naval Security Center on Nebraska Avenue in Washington after a search of him turned up a loaded .22 caliber revolver in his pocket, according to court documents.
At first, Wienke was stopped as part of routine random screenings at the entrance gate. DHS security agents found a folding knife, two-way radio, pepper spray, infrared camera, handcuffs and a breathalyzer in his backpack. The knife and pepper spray were confiscated and Wienke was allowed to go to his desk, according to an affidavit attached to a search warrant for Wienke's West Virginia residence.
An hour-and-a-half later, as a meeting of senior DHS officials was taking place across from Wienke's cubicle, law enforcement went to his desk and met him as he arrived shortly thereafter. Wienke denied having weapons on him, but a pat-down revealed a revolver loaded with hollow-point bullets in his pocket.
Wienke had a permit to carry a concealed weapon in West Virginia, but was not licensed to carry in Washington, according to the documents.
The arrest was first reported by NBC4 Washington.
Investigators believe that Wienke may have been plotting, possibly with another person, to carry out an attack on DHS, including possibly on senior officials that frequented and were housed in the highly secure complex where Wienke works. The officer signing the affidavit cited the infra-red camera, handcuffs, multiple handcuff keys, two radio devices and weapons Wienke had on him as evidence of such a threat.
"This provides probable cause to believe that Jonathan L. Wienke was conspiring with another to commit workplace violence, and most particularly may have been conspiring or planning to commit violence against the senior DHS officials in the building," wrote DHS investigator Eric Mann.
Mann also said that a law enforcement label on the pepper spray and the breathalyzer that Wienke were carrying suggest he or he and co-conspirators were planning to impersonate law enforcement officers.
In the search warrant for Wienke's residence, investigators said they were looking for more weapons, thermal imaging equipment, communications devices and paper trails for how Wienke acquired them, as well as any research on DHS personnel, potential targets, law enforcement paraphernalia and other evidence of a partner or broader plot.
Wienke was released from jail June 13 pending further proceedings. A spokesperson for the U.S. Attorney's office in Washington had no comment citing an ongoing investigation.
A DHS spokesperson said he has been placed on administrative leave during the pending the investigation.
One of the chief congressional watchdogs of DHS, House Homeland Security Committee Chairman Mike McCaul, expressed concern about the incident.
"Initial reports of this incident are very troubling, and my committee is looking into this serious matter," the Texas Republican said in a statement. "DHS has been in contact and we will continue to engage with the appropriate officials to gather all the facts."
Wienke and his attorney did not immediately respond to CNN request for comment.