National Guard Support Mission 2021
"Guardsmen supporting the Joint Task Force District of Columbia don protective gear at the D.C. Armory, Washington D.C., Jan. 9, 2021. National Guard Soldiers and Airmen from several states have traveled to the National Capital Region to provide support to federal and District authorities leading up to the 59th Presidential Inauguration. (U.S. Air National Guard video by Senior Airman Amanda Bodony)"
I don’t know Army shoulder patches that well - but those didn’t look like National Guard - I’m thinking they may have been 10th Mountain? based on what I could see from the badges on the right arms.... nope just checked not 10th Mountain. Definitely not Maryland National Guard as they have a multicolored patch with their state emblem on it.
Patch is a black upper color with two silhouetted white mountain peaks offset from center... maybe a regimental patch? Definitely appears to be active duty though