But the House of Commons Protective Services union says they're also satisfied that a report released Wednesday into what happened that day suggests they did their jobs properly.
The Ontario Provincial Police report concluded that the RCMP could have stopped Michael Zehaf Bibeau from making it into Centre Block, but for a series of miscues.
The report determined that Zehaf Bibeau was caught in a hail of gunfire within seconds of bursting through the front doors and died after being hit by 31 bullets.
The report makes 66 recommendations, including better weapons for the RCMP and identifies ongoing security issues, such as easy public access to the lawn of Parliament Hill.
The guards' union says they know there are structural and institutional elements that need improvement, but they'll continue to devote their lives to protecting what they call one of Canada's most fundamental institutions — the House of Commons.
Also on HuffPost