For weeks, Department of Homeland Security officials watched Portland protesters through security cameras situated around the Mark O. Hatfield United States Courthouse downtown, court records show.
But DHS also surveilled demonstrators from the sky.

Flight tracker data shows that on at least three occasions, airplanes owned by Homeland Security circled for hours over Portland protests—on the evenings of July 22, 28 and 29. Since July 16, DHS has restricted flights of all nondesignated aircraft within the airspace directly above Portland for "special security reasons." The restrictions remain in place through Aug. 16.

The planes made repeated, concentric circles over the city for hours, in a technique consistent with "dirtboxing"—when a circling plane equipped with Digital Receiver Technology, a DRT box, or a cell site simulator mimics a cellphone tower, effectively intercepting the signals of nearby cellphones. This allows government agents to retain cell phone data and track locations of those in radio range. (DHS did not respond to WW's questions about the type of surveillance conducted.)

"It's hard to say what they're doing, but we should all be pretty alarmed at how routine this type of surveillance is becoming in the wake of the George Floyd protests," says Brett Max Kaufman, a senior attorney at the American Civil Liberties Union's Center for Democracy.

Earlier this year, before President Donald Trump deployed federal agents to Portland protests, WW first reported that a small Cessna linked to the U.S. Marshals Service spent hours circling Portland protests on Saturday, June 13. The agency has never confirmed or denied whether it owned the aircraft, even after it received a letter from Oregon's congressional delegation demanding information by July 17.

"The Trump administration has failed to answer basic questions from June about federal law enforcement surveillance flights over peaceful protests in Portland," says U.S. Sen. Ron Wyden (D-Ore.), who sits on the Senate Intelligence Committee. "Willamette Week's new report raising questions about even more surveillance flights by another agency at Trump's direction adds to his alarming track record of abuse and disdain for constitutional oversight."

But the planes that circled Portland later in July weren't so mysterious. Both were Beechcraft Super King Air 350 twin turboprops registered to Homeland Security. Here are their flight paths over Portland.

Flight 1 | Tail number: N419K
Date: July 22-23, 2020
Departed: Bellingham International Airport (BLI) at 8:17 pm
Arrived: Portland International Airport (PDX) at 11:19 pm
(Brief layover at PDX)
Departed: Portland International Airport at 12:30 am
Arrived: Bellingham International Airport at 1:50 am
Time in air: 4 hours, 22 minutes
Flight pattern: After departing from BLI and arriving over Portland airspace, the plane made approximately 24 concentric circles above the city, narrowing in closer to downtown Portland. After 11 pm, it landed at PDX before departing again toward downtown Portland airspace, where it arrived again shortly after midnight July 23. The plane then made several more circles for about an hour above the city before returning to Bellingham.
Altitude: 8,100-10,100 feet
Total distance traveled: 1,017 miles
Speed: Approximately 200 mph

Flight 2 | Tail number: N541G
Date: July 28, 2020
Departed: Portland Hillsboro Airport (HIO) at 6:45 pm
Arrived: Portland Hillsboro Airport at 10:19 pm
Time in air: 3 hours, 34 minutes
Flight pattern: After arriving over Portland airspace from HIO, the plane made clockwise circles over North Portland. Beginning around 8 pm, it began making erratic circles as far northwest as Portsmouth and as far southeast as Foster-Powell. For the last 45 minutes, it made neat, concentric circles around downtown Portland before flying back to HIO.
Total distance traveled: 695 miles
Altitude: 10,000 feet
Speed: Approximately 200 mph

Flight 3 | Tail number: N541G (same as Flight 2)
Date: July 29-30, 2020
Departed: Portland Hillsboro Airport (HIO) at 10:02 pm
Arrived: Portland Hillsboro Airport at 12:41 am
Time in air: 2 hours, 39 minutes
Flight pattern: The plane departed from HIO and arrived over North Portland, where it began making clockwise circles. Near midnight, the plane moved south above downtown Portland, where it continued to make counterclockwise circles before returning to HIO.
Altitude: 10,500 feet
Total distance traveled: 502 miles
Speed: Approximately 200 mph