A tragic incident at Quebec's National Assembly will be commemorated with a plaque, Quebec Speaker Jacques Chagnon announced on the eve of the 30th anniversary of a gunman's rampage that left three dead and 13 wounded.

On May 8, 1984 deranged gunman Cpl Denis Lortie, 25, entered the National Assembly with a sub-machine gun and killed National Assembly messengers Georges Boyer, Camille Lepage and Roger Lefrancois. He wounded another 13 victims.

Sergeant-at-Arms Rene Jalbert persuaded Lortie to stop his rampage before more damage could be done.

Surveillance tape showed Jalbert calmly offering Lortie a cigarette (which he refused) during the attack. Jalbert later expressed pity towards the psychologically-distressed attacker.

"I guess I feel sorry for the poor little bastard. He was a very confused man with a young wife and two small children,” Jalbert later said about Lortie.

Jalbert was honoured with Canada’s Cross of Valour. He died of cancer on January 21, 1996, aged 73.

A jury found Lortie guilty of first-degree murder in 1985 but an appeals court ordered a second trial after finding fault with the judge’s instruction to jurors on how to evaluate psychiatric testimony.

Lortie was then sentenced to three counts of second-degree murder and was given life with a parole eligibility of 10 years. He was released on full parole in 1996.

Security at the legislature was greatly increased following the shooting. Unarmed constables have been replaced by armed guards supervised by a Surete du Quebec officer. Everyone - including MNAs - must show a special National Assembly ID card in order to enter. Visitors must enter through checkpoints equipped with metal detectors.

The bullet holes are still visible in the ornate woodwork of the assembly.