The Canadian intelligence community is still assessing how much damage Jeffrey Paul Delisle's spying activities have done.
The navy sub-lieutenant is undergoing a sentencing hearing after pleading guilty to funnelling top secret material to the Russians from his desk at HMCS Trinity, an intelligence hub based at the Halifax naval dockyard that routinely sees data shared by Canada's allies.
Though Delisle has kept silent since his arrest a year ago, evidence presented in court suggests the motive for the heavily indebted officer was money. He was paid almost $72,000 by Russian agents allegedly working out of the embassy in Ottawa.
Delisle is the first person tried and sentenced under the Security of Information Act, which CBC News noted gives the judge no earlier cases as a guideline for sentencing. The spy faces the possibility of life in prison.
Michelle Tessier, director general of internal security at the Canadian Security Intelligence Service, told the hearing the harm Delisle did is still being assessed.
"It's extremely concerning to us," she testified, adding that Delisle passed a number of names and contact numbers of CSIS agents to the Russians.
"For us, there is a potential loss of life," Tessier said. "There's an expectation that you will protect that information. It's all about trust. It's about trust. It's about confidence."
Questioned by defence lawyer Mike Taylor, Tessier admitted she doesn't know all of what Delisle gave to the Russians, CBC News reported.
"There's a lot of uncertainty," said Taylor. "You're still offering opinion without definite confirmation."
But Tessier maintained the damage was "very severe."
Her conclusion was echoed by Brig-Gen. Rob Williams, the Department of National Defence damage assessment officer, who said the breach "could cause exceptionally grave damage to the national security of Canada." The department is going on the assumption everything that passed through Delisle's hands was handed over to the Russians.
The spy scandal embarrassed Canada with its allies in the intelligence community.
Delisle's workplace handled information under the so-called Five Eyes intelligence-sharing arrangement between Canada, the United States, Great Britain, Australia and New Zealand. If its allies aren't satisfied security has been tightened, Tessier said, "there's a risk we may be cut off."
[ Related: Delisle spy story elicits shrugs from allies ]
In his cross-examinations, Taylor drew admissions security at HMCS Trinity was lax.
"There were problems, yes," Williams testified, according to The Canadian Press. "Things were missed."
Taylor's only witness on Delisle's behalf was Wesley Wark, a University of Toronto professor and expert on security and intelligence.
Wark testified Thursday it would be hard for the intelligence community to prove Delisle caused much real damage because police intercepted only two attempted transmissions during the almost five years he was spying for the Russians, CP reported. There was no evidence the Russians responded to the material, he said.
"It is, in a way, theoretical harm," Wark said. "To be honest, it is very difficult to assess the harm he has done."
As for Canada being shunned by its allies when it comes to sharing intelligence, Wark observed other countries have experienced more serious breaches without being frozen out, CP reported.
"It is a real reach to say that Canada will suddenly be cast out," he said. "I can't imagine we'll be cast out."
Delisle sat largely silent during the hearing, except to respond to basic questions from Judge Patrick Curran about the facts of the case.
Delisle joined the navy as a reservist in 1996 and became member of the regular forces in 2001 and an officer in 2008.
Crown prosecutor Lynne Decarie told the court Delisle walked into the Russian Embassy in 2007 to offer his services as a spy in exchange for money, receiving a total of $71,817 from 2007 to 2011, CP said.
He used his position to search for references to Russia in intelligence material, copy the information onto a floppy disk on his secure computer, then transfer it onto a memory stick on a non-secure computer, the prosecutor said.
Delisle came under suspicion in September 2011 after returning from Brazil, where he met a Russian agent named Victor. Canada Border Services agents became suspicious because he arrived home with no tan, little knowledge of the place he'd just visited, thousands of U.S. dollars, three prepaid credit cards and a handwritten note containing an email address, said Decarie.
He was arrested in January 2012 after trying to send secret "Canadian eyes only" documents to his Russian handlers, information that was part of an RCMP sting.
The federal government ordered the expulsion of four Russian diplomats soon after Delisle was arrested, though neither the Russians nor Ottawa would make the connection to the case.