The Garda Commissioner, Mr Pat Byrne, has said it is too soon to judge whether security should be stepped up at Garda stations to protect members of the force.
He said the Garda would "analyse what happened" in Tallaght station yesterday morning, but it was "too early to speculate" whether the layout of stations would be changed.
After meeting the Minister for Justice, Mr Byrne was asked if gardai had been expressing concern about open-plan buildings and security. He replied: "It was never really an issue."
The Garda is "a police force that's very accessible to the people," he said. That was something he did not "intend changing in any way. I fully support the whole concept of openness with the Garda Siochana in its interaction with the community, so let's not have a knee-jerk reaction to something because of this terrible tragedy."
Speaking earlier outside Tallaght Garda Station, Mr Byrne said the circumstances of Sgt Callanan's death would "not in any way affect how we police this community because we can only police this community with the support of this community, and that's the way we intend going forward in the future".
While every member of the force knew that policing was "a hazardous business", nobody "could have anticipated something like this happening".
Mr Byrne continued: "It's a black day for the Garda . . . Sgt Callanan was a fine police officer."
He said his thoughts were with Sgt Callanan's family, especially his wife and children.
A book of condolences for Sgt Callanan has been opened to the public at South Dublin County Council offices in Tallaght.
