Political Motives
The Royal Canadian Mounted Police (RCMP) said Cirillo's suspected killer, Michael Zehaf-Bibeau, 32, made a video of himself saying the attack was motivated by his opposition to Canadian foreign policy. The RCMP said the video also showed he had religious motives.
Officials have also described Vincent's killer, 25-year-old Martin Rouleau, as a man motivated by radical beliefs.
Both attackers were shot dead by security services.
Following Cirillo's funeral, Harper is to meet with US Secretary of State John Kerry, who will travel to Ottawa to express his condolences over the attacks.
"The secretary will emphasize steadfast US support for our Canadian partners, continued close cooperation and a shared approach to countering violent extremism, and our commitment to stand beside our Canadian neighbors and friends," Jen Psaki, a spokeswoman for the US State Department, told reporters on Monday.
Cirillo joined the Argylls in 2007, shortly after he graduated from high school. He is survived by his mother, stepfather, two sisters and young son. He was fond of dogs, and in the days after his slaying images of two of his dogs peering out from under a fence, apparently awaiting their master's return, were widely circulated on social media.