Minneapolis police officer Mohamed Noor killed Damond in July after she called 911.
Four months on and no charges have been laid.
A decision is expected by the end of the year.
Investigators will decide whether to charge Officer Noor by the end of the year.
The slain Australian has been farewelled in Minneapolis.
WASHINGTON ― Six days. That’s how much time passed after a Somali-American cop in Minneapolis fatally shot a white Australian
The police car was allegedly "slapped" by a woman before Justine Damond was killed.
Meanwhile Mohamed Noor has still not spoken to investigators.
The witness has been interviewed by investigators.
The calls for her resignation come after Police Chief Janee Harteau steps down.