Fifteen years after a shooting rampage that killed four, a former Concordia University professor returned to a Montreal court Monday to pursue a lawsuit alleging that former co-workers profited from his research.

Valery Fabrikant is serving a life sentence with no chance of parole for 25 years for the Aug. 24, 1992, shooting at the Montreal university, which killed four of his colleagues and injured a fifth.

Speaking in Quebec Superior Court, Fabrikant said the attack was against co-workers trying to steal his ideas, and thus he cannot be compared to Marc Lepine, who killed 14 women at Montreal's École Polytechnique.

"There is nothing in common," he said. "He killed innocent people, I didn't."

From his conviction in 1993 until an order to stop in 2000, the former engineering professor flooded the court system with appeals, lawsuits and other legal requests. In a 2000 ruling, the Quebec Superior Court found him a "vexatious litigant" and prevented him from filing any legal proceedings with the court unless granted permission by the Chief Justice.

The current lawsuit, filed in 1992 and predating his conviction, alleges that five of Fabrikant's colleagues profited from his research on scientific articles published during the '80s, according to the Concordia University website. The university is not a direct party to the lawsuit.

Fabrikant is seeking a total of $600,000 in damages from former Concordia professors, who he alleges profited from his research and "extorted" his documents.

He has also requested, as part of the case, to have his status as a "vexatious litigant" cleared, to access computer software and have some witnesses testify by phone.

Representing himself, Fabrikant repeatedly questioned Justice Gilles Hebert's methodology and scoffed at one of the judge's rulings during Monday's court session.

He requested a larger table in the prisoner's box, and when it was rejected, asked Hebert, "What's so special about you?"

Fabrikant is expected to take the stand on Wednesday after Hebert rules on his motions.

With files from the Canadian Press