Authorities said 15-year-old transgender teen was wounded in the attack and a man was arrested at the Fort Totten station.
Unidentified woman who apparently fainted on Farragut West platform was pulled from tracks by others in the station.
Signs at only a handful of stations will always display next Blue Line arrival times.
Dennis Anosike replaces Carol Kissal, who resigned as Metro's chief financial officer after a critical audit report.
No scheduled disruptions along new line's route.
After simulating Silver Line service all day Sunday and Monday morning, transit authority says the new rail route is glitch-free so far.
Silver Line testing this week means a different view from platforms on four of the other five lines.
One site puts the station closer to residential neighborhoods; the other is closer to retail and mixed-use development.
The region's first rapid bus transit system, Metroway, will start service Aug. 24.
Trespasser claimed to be mixing chemicals. A search has found nothing dangerous.