MONTREAL -- A former Montreal university professor who fatally shot four academics in 1992 has once again been declared a vexatious litigant, this time by the Federal Court of Appeal.

Justice David Stratas recently ruled that Valery Fabrikant, who is serving a life sentence in Quebec, unduly wastes the resources of other people and the court through the many legal procedures he's initiated from behind bars.

Fabrikant, now 79, was an associate professor of mechanical engineering at Concordia University.

He was facing dismissal when, in August 1992, he went into the engineering department and opened fire, killing four academics and wounding a secretary.

Stratas noted that Fabrikant meets the criteria of a vexatious litigant, which includes filing lawsuits with little merit, trying repeatedly to file appeals without obtaining leave and making unfounded accusations of bias, incapacity or fraud against members of the court.

The Federal Court and Quebec Superior Court have previously given Fabrikant the designation, which means he generally needs permission before filing further lawsuits.

Among his previous lawsuits was one in which he claimed his former Concordia colleagues had stolen his work -- a case he ultimately lost when the Supreme Court of Canada refused to hear the case.

In 2014, however, he won a bid to be granted a second winter parka after an appeal court decided there was no good reason for prison authorities to deny him one.