Politicians will return to Parliament Hill for work on Monday, and the historic buildings will be open to the public and for tours for the first time since Wednesday's shootings.

Experts say they expect to see two main changes implemented almost immediately on the Hill, along with new laws and communication strategies down the road.

Immediate changes will likely involve tightening security -- both at Parliament’s gates and inside the buildings themselves -- plus increasing co-ordination between the various police and security forces.

"I think one of the big lessons learned is there has to be some kind of perimeter beyond the front doors of Centre Block," University of Ottawa Law Professor Errol Mendes told CTV News Channel Sunday. He expects more officers or guards to be standing outside doors where lawmakers are meeting.

Mendes added: "There has to be more integration between the RCMP, who covers the grounds of Parliament, and the internal security people in Parliament."

Parliament Hill was thrown into an hours-long lockdown Wednesday after Cpl. Nathan Cirillo was shot and killed at the National War Memorial. The gunman then fled to the Hill, breaching the front doors and opening fire in Centre Block before being fatally shot by Sergeant-at-Arms Kevin Vickers.

Officials said about 70 rounds of ammunition were fired at the gunman, Michael Zehaf-Bibeau.

Parliament Hill quietly re-opened to the public late Friday, after MPs and other staffers had left for the week. The Ontario Provincial Police, at the request of the RCMP, will lead an independent investigation into Wednesday's events. Additionally, House of Commons Speaker Andrew Scheer has ordered a full review of Parliament Hill security.

Alexander Corbeil, a senior research analyst at the NATO Council of Canada, agreed that immediate changes are likely to be seen on Parliament Hill Monday. But he also said the government needs to prevent individuals from wanting to commit attacks in the name of radicalism in the future.

Before Wednesday's incident, Warrant Officer Patrice Vincent was killed when a 25-year-old Quebec man ran down two Canadian soldiers with his car in St-Jean-sur-Richelieu Monday. The suspect, Martin Couture-Rouleau, was killed by police, who said he had become radicalized.

"We have to work with organizations that can deal with individuals who are at risk of being radicalized, or who have already been radicalized, before they carry out violent acts," Corbeil said.

He suggested the government needs to do a better job of showing what will actually happen if Canadians decide to join ISIS. "We have to present a counter-narrative to ISIS's very slick and savvy multi-lingual media campaign," he said.

Difficulty with creating new laws

Mendes said he also expects the Tory government to introduce a new bill this week to give CSIS more powers to track certain individuals in Canada and abroad. However, he said crafting a new law to protect security without limiting freedom is one of the hardest challenges faced by government and all Canadians.

"When you look at these two individuals who have killed the two military officials, they are lone wolves," said Mendes. "They are more troubled individuals with mental problems than the type of classic terrorist that has conspired with others to commit a major crime."