D.C.'s police chief is calling for one of his officers to step down after federal prosecutors decided not to charge the officer who shot and killed an unarmed black motorcyclist.

D.C. Police Officer Brian Trainer shot 31-year-old Terrence Sterling in northwest Washington Sept. 11, 2016.

On Wednesday, the U.S. Attorney's Office announced there was "insufficient evidence" to charge Trainer in Sterling's death. The announcement quickly led to protests and calls for the officer to resign -- including from D.C. Mayor Muriel Bowser.

D.C. Police Chief Peter Newsham said Thursday he has asked Trainer to resign.

"What I would say about a resignation is that when he is deciding whether or not to resign, he needs to consider the family and the impact that this could potentially have on the city," Newsham told News4.

Bowser renewed her call for Trainer to step down Thursday, saying the public deserves accountability.

"I believe if there's no accountability in this incident that we break trust with our community," Bowser said at a news conference.



Following the decision by the U.S. Attorney's Office, the police department has 90 days to review the incident to see if department policies were violated.

"We have to focus on, really, what we can control here at MPD, and the two things that I can control right now is to make sure that we do a very complete and thorough investigation. That we get the Sterling family the answers to the questions that they have and to try to do that as quickly as possible," Newsham said.

D.C. Councilmember David Grosso, who has been critical of the police department in the pas, says Officer Trainer's actions the night he shot Sterling are cause for a bigger concern.

"I think they also need to dig a little deeper and see where the systemic problems are. These guys were trained MPD officers and chose to completely ignore the rules of MPD. So, how can that happen? Why does it happen? And further investigation into the full system needs to be done as well, not just the actions of these two guys, which was very inappropriate," Grosso said.