The Ministry of Social Development has told MPs it has taken steps to change security measures at its Work and Income offices, and the way it interacts with its clients.
The ministry was convicted of breaching workplace safety legislation after the fatal shooting of two staff members at its Ashburton office in September 2014.
Leigh Cleveland and Peggy Noble were killed by Russell Tully and a third staff member was wounded.
MSD chief executive Brendan Boyle told Parliament's social services committee a number of changes had been made to office lay-outs and extra security measures installed.
And he said there had been a greater emphasis on staff training.
"De-escalation training, training and working with our security guards ... doing everything we can to de-escalate issues and to train people and to recognise a problem and try and mitigate it."
"The way we greet, they way we interact whether that's on the telephone or in person, the lay out of the offices, the nature of the engagement and the way people are treated acknowledging that that in itself can have a lot to do with de-escalating tension."
Mr Boyle also said there was a now a zero tolerance approach to threats made to staff, which were now reported to the police, which had not always happened in the past.