A Canada-wide arrest warrant has been issued for a 43-year-old Ontario man who is wanted in connection with the death of his seven-year-old stepson and the attempted murder of a bank employee.

Niagara Regional Police Const. Phil Gavin tweeted on Monday that police had received judicial authorization for the warrant.

Justin Kuijer, a resident of St. Catharines, Ont., is wanted on charges of second-degree murder in the death of Nathan Dumas, 7, and attempted murder in connection with an attack on a bank employee.

Nathan Dumas was found critically injured in his home by his mother on Friday and died the next day in hospital. Police have not yet released the cause of death.

Police also said a female Royal Bank employee was stabbed by a man who entered the branch. The incident was not a robbery and the employee and the man knew each other professionally, police said.

CTV Toronto’s Austin Delaney reported that the woman was stabbed at the same branch where Kuijer had recently been turned down for a loan. The bank employee was taken to hospital where she’s currently in stable condition.

Const. Phil Gavin said the boy’s mother has been aiding police in their investigation.

“She’s in a position where she’s trying to help us and support us in our efforts to locate him but she’s also grieving in a terribly tragic situation at the loss of a son,” he said.

Nathan’s mother, Whitney Dumas, posted a message on Facebook on Sunday thanking the community for its “overwhelming support” and praising the Niagara Regional Police for their work. She also asked the public to allow her family to grieve her son’s death in peace.

“I kindly ask that everyone respect my families (sic) privacy and space, and allows my family this time to mourn the loss of my beautiful son,” she wrote.

Members of the community have created a makeshift memorial with flowers and stuffed animals outside the steps of Nathan’s home. The family has also started a GoFundMe campaign in order to raise funds for his funeral.

Manhunt underway

As of Monday morning, police said they still don’t know where Kuijer may be headed.

“We face the problem that this occurred at 10:25 a.m. on Friday morning,” Gavin said. “We obviously know he has access to a vehicle. It’s now Monday morning. So (in terms of) drive time, he could make some distance between Niagara and wherever he wants to go.”

Investigators said Kuijer was last seen driving a dark grey 2009 Pontiac Montana van with the license plate BYTE392. The vehicle has a distinctive pink flower decal on the rear driver’s side window. The suspect was last seen wearing an orange hooded sweatshirt under a brown leather coat, dark pants, a black toque and boots.

Police described Kuijer as armed and dangerous. They advised the public not to approach him if they see him and to call 911 instead.

Kuijer is being urged by police to hire a lawyer and negotiate his surrender.

None of the allegations have been tested in court.

With files from CTV Toronto and The Canadian Press