The alleged gunman, Ali Rachid Ammoun, 63, is in custody and has been charged with a series of firearm offences for the shooting on August 14.

No one was harmed when Ammoun allegedly shot his handgun at a window of the airport from inside the lobby.

ACT police have asked their NSW counterparts to call for witnesses as they believe there are still many people they are yet to speak to.

This includes anyone who witnessed any suspicious behaviour.

Ammoun's case returns to court on September 5. The NSW man is yet to enter a plea.

He has been charged with discharging a firearm at a building, unlawful possession of a firearm and discharging a firearm near a person causing alarm.

Police allege Ammoun fired a number of shots from a handgun into windows about 1.25pm on Sunday before being apprehended by federal police stationed at the airport.

Ammoun had not passed into the terminal and so had not been screened.

No one was injured during the incident but the airport was evacuated and remained closed for about three hours.

Canberra Airport boss Stephen Byron said there were no plans to introduce further security.

Australian Associated Press