The search is over for an Ontario man accused of fatally injuring his seven-year-old stepson moments before allegedly stabbing a local bank employee.

Niagara police Chief Jeff McGuire confirmed that Justin Kuijer, 43, was arrested by provincial police Tuesday in Kenora, Ont., after a tip from a citizen.

A Canada-wide arrest warrant was issued Monday for Kuijer on charges of second-degree murder in the death of seven-year-old Nathan Dumas, as well as the attempted murder of a woman working at a local RBC branch.

Police alleged that Kuijer had been on the run in his ex-girlfriend's van ever since the two grisly scenes unfolded Friday.

In a news release, Niagara regional police said the 2009 Pontiac Montana van was located at about 5:15 p.m. Tuesday in a parking lot with Kuijer alone inside. They said he was arrested without incident.

He is expected to be returned to the Niagara Region within the coming days, police said.

Police have said that they were called to a home Friday morning above a sandwich shop owned by Nathan's grandparent.

Const. Phil Gavin said a family member found Nathan suffering from critical injuries and had him rushed to a hospital, where the boy died the next day.

At around the same time the Dumas family was making the discovery, police allege Kuijer walked into a nearby RBC branch and stabbed a woman working there. Gavin said Kuijer - who is listed as the owner and operator of Niagara Elite Roofing - had a professional relationship with the woman.

The officer described the attack as targeted, but declined to provide further details.

The woman is now in hospital in stable condition, he added.

Police had originally indicated that they would be seeking a charge of first-degree murder in Nathan's death, but Gavin did not explain why the second-degree murder charge was listed on the warrant.

“At the 11th hour the decision was made that this was the most appropriate charge,” he said.

When reached by phone Monday, the boy's mother, Whitney Dumas, declined to comment, but she addressed the loss suffered by herself and her two other children in a series of Facebook posts.

“This is truly a tragic time for everyone involved,” she wrote. “I understand that everyone has questions, it's human nature, so do I. I kindly ask that everyone respect my family's privacy and space and allow my family this time to mourn the loss of my beautiful son.”

Dumas thanked the Niagara community for an outpouring of support and a wave of financial generosity, and social media comments suggested those beyond the family circle also felt moved by Nathan's death.

“My kids and I said a prayer tonight for you and your family,” wrote one Facebook user. “You not only have a city, but a region ... probably a nation at this point ... supporting you.”

An elementary school near the scene where Nathan died flew a flag at half-mast on Monday afternoon, and crowdsourcing efforts to raise money for the family generated considerable response.

Friends of the boy's family started a GoFundMe campaign that had netted more than $21,000 by Tuesday night.

The page suggested Nathan died just a week shy of his eighth birthday.

“Nathan's precious life was abruptly cut short at the hand of someone else,” the tribute said. “Nathan was an energetic, loving and caring little boy who will never have his first girlfriend, graduate school or get married and have children. Nathan would have made a big difference in this cruel world.”