Back in the 1990s, Steve Rambam posed as a university researcher to get war criminals to tell him their stories.

In Hope, B.C., he interviewed Antanas Kenstavicius.

“He was a police chief in Lithuania and his unit, under supervision of Germans, rounded up 5,000 Jews. They were locked up for a week, the women raped, their belongings looted. Then they lined them up naked in the ditch… it took them six days to kill them all by gunfire. This guy was telling me all this matter-of-factly. He told me: ‘Then on Nov. 19, no more Jews.’”

It took them six days to kill them all by gunfire. This guy was telling me all this matter-of-factly

Proceedings to deport Mr. Kenstavicius began in 1997; the 90-year-old died the same day.

The case was not the first, or last, Canadian failure to bring suspected Nazi war criminals to justice.

Nazi hunter @StevenRambam to speak in Toronto, June 24. Fundraiser for United Chesed unitedchesed.com/store/c1/Featu… http://t.co/j7ePBd2mr0 —

Dave Gordon (@davegordonwrite) May 13, 2014

It is estimated that between 2,000 and 5,000 war criminals fled to Canada after the Second World War, but not one Nazi has ever been successfully prosecuted in this country.

“It is to the Canadian government’s great and eternal shame that more was not done,” said Mr. Rambam, the renowned “Nazi hunter” who will be in Toronto on Tuesday for a charity event.

Activists say it’s not too late for Canada to act. A handful of cases are still actionable.

Looking back, a key problem was that for decades Canada did not actively pursue suspected war criminals, and when it did decide to launch proceedings they were done badly and ineffectively, said David Matas, senior legal counsel of B’nai Brith Canada.

“Canada started too late; there were just too many perpetrators; too much evidence had been destroyed or lost. The effort was more an attempt to construct a justice legacy for the victims of the Holocaust,” said Mr. Matas.

The seeds of Canada’s inaction were sown three years after the end of the war. The allied powers decided that prosecuting war criminals would end and the British Commonwealth Relations Office wrote to the dominions explaining the policy.

The punishment of war criminals is more a matter of discouraging future generations, than of meting out retribution

“In our view, the punishment of war criminals is more a matter of discouraging future generations, than of meting out retribution to every guilty individual,” wrote the department, as revealed by Franklin Bialystok in his book Delayed Impact: The Holocaust and the Canadian Jewish Community.

The letter went on to say it was “now necessary to dispose of the past as soon as possible.”

In 1985, pressure from the Jewish community led Brian Mulroney to set up a Commission of Inquiry on War Criminals, headed by Jules Deschênes. The Deschênes Commission put forward the names of 883 suspects.

From 1987 to 1992 just 26 cases were filed before the justice system; charges were laid under the Criminal Code in four cases.

The man in the dock in 1987 was Imre Finta, the first suspect to be accused under new laws on war crimes. Mr. Finta, who came to Canada in 1948 and died here in 2003, was accused of being a key official in the rounding up of Jews in Szeged, Hungary, in 1944 and sending them to Auschwitz and to Strasshof.

His acquittal in 1990 shut down any hope of winning criminal proceedings against Nazi war criminals.

“Finta presented no evidence to answer the charges against him,” Mr. Matas said. “When asked if he wanted to call evidence on his own behalf at his criminal trial he declined. Yet he was acquitted.”

Why? The courts allowed a defence that said believing Jews to be the enemy was a legitimate reason for killing them.

Two appeal courts agreed.

Parliament later legislated to overturn the reasoning in the Finta case in 2005. But by then it was too late to recommence prosecutions, Mr. Matas said.

After the failure of criminal prosecutions, the government in 1995 announced it would use such administrative measures as revoking citizenship and ordering deportation.

Under this new course of action, two men were extradited and five deported.

Bernie Farber, former head of the Canadian Jewish Congress, calls a 90-year-old Kitchener, Ont., man, Helmut Oberlander, the “final symbol” of Canada’s failure on this issue.

In fact, three cases could still be acted on: those of Mr. Oberlander, Vladimir Katriuk, and Wasyl Odynsky.

Mr. Oberlander was part of a Nazi killing squad, Einsatzkommando 10a, which operated in the eastern occupied territories during the Second World War. Mr. Oberlander admits to serving with the “German armed forces” but says he never subscribed to the Nazi ideology or participated in any killings.

A judge ruled in 2000 that Mr. Oberlander worked, lived, and travelled as an interpreter for a Nazi mobile death squad and, although there was no evidence he participated in atrocities, he must have been aware of them.

Mr. Oberlander has been fighting attempts to strip him of his citizenship and deport him since 1995.

There is no justification for continuing to give him a haven

In 2008, he was stripped of his citizenship for a second time, but in 2009, the Federal Court of Appeal instructed the federal cabinet to reconsider because of Mr. Oberlander’s assertion that he joined the squad as an interpreter under duress.

In 2012, Mr. Oberlander, a Ukrainian Canadian, was again stripped of his citizenship and immediately mounted a counter challenge. The Federal Court heard the appeal in February this year, but has not yet released a decision.

Mr. Oberlander could not be contacted for comment.

Vladimir Katriuk, ranked No. 4 on the Simon Wiesenthal Center’s most-wanted list, came to Canada under a false name in 1951.

In 1999, the Federal Court ruled he had obtained his Canadian citizenship by misrepresentation, but found there was no evidence he had committed atrocities. The cabinet decided in 2007 not to revoke his citizenship

New evidence in the case came when declassified records released in 2008 documented that a man with the same name as Mr. Katriuk, currently in his 90s and living on a farm in Ormstown, outside of Montreal, was a commander of a platoon in a battalion that perpetrated a massacre in a Belarusian village in 1943, and that he personally opened fire with a machine gun.

B’nai Brith wrote to the government in 2011 urging that the government reverse the Katriuk decision.

“The information we now know about Mr. Katriuk makes it unconscionable for the existing decision … to stand. There is no justification for continuing to give him a haven in Canada,” it said.

The organization never got a response.

Mr. Katruik has consistently refused to talk publicly about his past. His wife told the National Post on Thursday that he would not be answering any questions.

Wasyl Odynsky came to Canada in 1949. Mr. Odynsky, 90, who had been living in Toronto but whose whereabouts are not known, was accused of serving as a guard at two forced labour camps and in an SS battalion. While a Federal Court ruled in 2001 that he had lied to gain entry to Canada, it also found that he was unlikely to have participated in a massacre of Jewish captives.

In 2007 the government decided not to take away his citizenship.

B’nai B’rith is also challenging that decision.

Mr. Rambam, the U.S. private investigator who will speak at an event for impoverished Jews in Toronto on Tuesday, believes scores of war criminals are still living in Canada.

“Entire units came en masse into Canada through Halifax in the 1940s,” he said. “Canada knew at that time who they were.

“If there are a few cases that can still be brought, just for the sake of doing the right thing, then that should happen.”

“None will live long enough to make it to trial, they will hire excellent lawyers. … They’ll delay and throw legal roadblocks in the way until they have died safely in their beds, but it’s the point of doing it.”

It was the justice system itself that in the end let us down

Mr. Rambam interviewed 72 out of a list of 1,000 suspected Nazis living in Canada. His work was sent to the authorities, but he said little was done.

“It’s a stain on the history of Canada,” he said.

Mr. Farber views things slightly differently.

“The government did look at this matter with laser focus, so I think we have to give them credit … they tried. It was the justice system itself that in the end let us down.”

Paloma Aguilar, a spokeswoman for the Department of Justice, said individuals who have been involved in war crimes or crimes against humanity would find no haven in Canada.

“The Deschênes Commission put forward the names of 883 suspects. To this day, federal authorities have investigated upward of 2,000 files,” she said.

“The government continues to receive allegations, all of which are examined.”

National Post