Conservative Sen. Vern White, a former police chief, says the new security plan will consider a range of scenarios — from a "lone wolf" incident to a co-ordinated, well-planned assault like the one on Charlie Hebdo last week.
"We are reacting and considering all possibilities," White said Tuesday during a lunch-hour panel program on Ottawa radio station CFRA.
Everyone knows Michael Zehaf Bibeau's bloody rampage in Ottawa could have been much worse, and security planners recognize the need to protect against better-armed, more co-ordinated attackers, he added.
White said that ought to include reinforcing Parliament Hill's outer perimeter, which extends at least the length of a full city block away from the front doors of the Centre Block, the iconic building that includes the Peace Tower.
"To be blunt, you need to kill them at the gates, you need to kill them on the lawn, you need to kill them outside the building," he said.
"You can't afford to let them get inside the building. So, whatever the plan looks like to make that reality is what you have to work towards."
Improved security at the edge of the property could involve RCMP officers restricting the number of access points to three from five and conducting searches at those entrances, White suggested.
He said he's proud of the fact Parliament Hill is so publicly accessible, but noted there are lots of opportunities to improve security without disrupting the public's access to the country's seat of democracy.
Last November it was announced that the House of Commons and Senate security officers would patrol the parliamentary precinct under a single command. Members of the unified parliamentary security team have been trained to carry firearms.
Following the fatal shooting of Cpl. Nathan Cirillo at the National War Memorial on Oct. 22, Zehaf Bibeau ran up the eastern driveway of Parliament unchallenged before he hijacked a minister's waiting car and drove the rest of the way to the front doors.
After running into the Centre Block, Zehaf Bibeau was shot and killed by Kevin Vickers, the Commons sergeant-at-arms, and RCMP security.
House of Commons Speaker Andrew Scheer ordered a full security review immediately following the attack.
Other interim security measures were imposed, including putting security posts outside the Centre Block to screen visitors and ensuring public tours don't take place while party caucus members are having their weekly meetings.
Scheer, who co-chairs the advisory committee with White, also said at the time to expect more changes.
At the end of November, the speaker asked the Ontario Provincial Police to investigate not only the shooting of Zehaf Bibeau in the Centre Block, but also the gunman's approach from Wellington Street to the doors of the building.
It is standard practice for an outside police agency to investigate when a police force is involved in a fatal shooting, but the second review — ordered a month after the first — suggests questions are being asked about how the perimeter was breached.