WASHINGTON (AP) – The commanding general of the District of Columbia National Guard is becoming the House’s first African American sergeant-at-arms. Maj. Gen. William Walker will lead House security measures as Congress is still dealing with the aftermath of the Jan. 6 attack on the Capitol and figuring out how to keep lawmakers safe. Walker was closely involved with the security that day as he sent troops to back up overwhelmed Capitol Police. He will replace Paul Irving, who resigned immediately after the insurrection. Walker’s appointment comes as the House is ramping up its investigations into the insurrection on Jan. 6.