In an artist's sketch, Mohammad Momin Khawaja, second from left, is shown in an Ottawa courtroom last month at the start of his trial. (Tammy Hoy/Canadian Press)E-mails written by Mohammad Momin Khawaja praising the Sept. 11, 2001, attacks as the "most effective and honorable way" of conducting "economic" jihad can be used as evidence in court, the judge ruled Monday at the terrorism trial in Ottawa.

In his decision, Justice Douglas Rutherford rejected arguments from the defence that the e-mails were prejudicial. He said they offer important insight into Khawaja's state of mind.

Khawaja, 29, the first person charged under Canada's Anti-terrorism Act, is on trial on seven charges for his alleged connection to a plot to set off a fertilizer bomb in England. As part of the charges, he is accused of building the remote-control device for detonating a bomb. Khawaja has pleaded not guilty.

Five of Khawaja's alleged co-conspirators were convicted last year by a British court and sentenced to life in prison.

Rutherford's decision came as the prosecution began wrapping up its presentation against Khawaja, a former software developer who was working for the federal Foreign Affairs Department when he was arrested in 2004 as part of a joint British-Canadian investigation.

'Imagine if there were 10 Sept. 11's'

The e-mails in question were sent to the woman Khawaja was planning to marry, Zeba Khan.

In one communication in particular, Khawaja goes on at length about his interpretation of jihad. He refers to economic jihad, or holy war, as being important to cripple and bankrupt enemy governments and economies.

"We need [constant] economic J [jihad] blow after blow until they cripple and fall never to rise again," he writes.

In another e-mail, he writes: "What did Sept. 11 do to America? Because of Sept. 11 the airline industry is dead, travel and tourism dead, the U.S. dollar is dead and the economy is practically in a state of recession … Would you not say that the actions of 19 men on Sept. 11 are the most accurate, effective and honorable way of conducting economic J? Imagine if there were 10 Sept. 11's."

Khawaja also writes that he knows innocent human beings died in the attacks on the World Trade Center and the Pentagon, but then argues there is "absolutely no other way to achieve the same objective with the same effect."

Not on trial for thoughts, defence argues

During submissions last week, Khawaja's lawyer, Lawrence Greenspon, insisted his client was not on trial for what he thought.

He argued the Crown aimed to suggest that if Khawaja supported attacks in Israel and New York, he must also be the kind of person who would back a bomb plot in London.

That's a "gargantuan leap" of logic that would violate the concept of freedom of thought enshrined in the Charter of Rights, Greenspon said.

No proof yet in e-mails, judge stresses

Rutherford ruled that while the e-mails in question could be prejudicial, the activities Khawaja is accused of are so serious that the court needs as much information as possible to make a decision.

The judge stressed he has not drawn any conclusions or proof from the e-mails yet, but said he wants the option to consider them when it does come time to decide Khawaja's case.

Rutherford added that some of the evidence already heard in relation to the case is so sinister and chilling that the e-mails aren't likely to shock or inflame anyone involved.

Khawaja is being tried by Rutherford without a jury. The trial is expected to run until October or November.

With files from the Canadian Press