Shooter was perched on doorway of H-212 Members Reading Room that connects to Speakers Lobby. Ashli was coming through the Speaker's Lobby door on the opposite side of the hall. The shooter advanced forward out of the doorway towards Ashli before he shot her.

https://en.wikipedia.org/wiki/United_States_Capitol#/media/File:US_Capitol_second_floor_plan_1997_105th-congress.gif

Shooter was perched on doorway of H-212 Members Reading Room that connects to Speakers Lobby.

https://en.wikipedia.org/wiki/United_States_Capitol#/media/File:US_Capitol_second_floor_plan_1997_105th-congress.gif