The head of Quebec's jail guards union says there was little officers could have done to stop three inmates who escaped from the Orsainville Detention Centre in suburban Quebec City in a helicopter over the weekend.

Mathieu Lavoie said the province's jail guards aren't equipped for such situations.

"What can we do against a helicopter? Yes, we have armed guards around the prison, but the rules of engagement prevent them from firing on vehicles, and even less so at helicopters," he said.

You don't know if the pilot is a hostage. It's better to let it go and to catch them afterward than to open fire on a flying aircraft. — Michel Martin, retired provincial police officer

Michel Martin, a retired provincial police officer, told CBC News that shooting at a helicopter would not be advisable even if it was permitted.

"You don't know if the pilot is a hostage. It's better to let it go and to catch them afterwards than to open fire on a flying aircraft that's maybe going to fall on your head," he said.

Both Lavoie and Martin said the addition of steel cables across open spaces in jails where a helicopter could land is needed in Quebec. A similar escape happened at a correctional facility in St-Jérôme in 2013.

On the federal side, Transport Minister Lisa Raitt said her department will look at any requests made to Transport Canada to make prisons more secure against aerial attacks or approaches. However, she said, because the jail is a provincial one, there wouldn't be much done at the federal level until the province moves first.

Prison routines make escapes easier

Martin also said the fact jails keep inmates on scheduled routines makes planning such escapes easier.

"If always you keep the same pattern, people looking to escape know the right time to try," he said.

A spokesperson for Quebec's public security minister said the department is looking into what changes can be made to prevent similar escapes from happening again.

Lavoie was also critical of the fact that some of the strict security conditions imposed on the three escaped men — Yves Denis, Denis Lefebvre and Serge Pomerleau​ — had recently been reduced.

Public Security Minister Lise Thériault told reporters Monday she wondered why the inmates' security conditions were relaxed.

Court case proceeds despite escape

Beauchesne also said Monday that the Quebec Superior Court was going ahead with the drug-trafficking case against his fugitive client.

Denis, Lefebvre and Pomerleau are facing multiple court proceedings on various charges, including drug trafficking, premeditated murder and gangsterism.

Beauchesne couldn't say what new charges his client could face as a result of his escape.

A fourth man who is facing the same charges as the three escaped inmates will go to trial without them. Radio-Canada is reporting that Thierry Béland was part of the escape plan but did not make the helicopter.

The murder charges the men are facing, which are scheduled to be prosecuted in January 2015, are connected to the deaths of two men, Johnny Coutu and Benoît Denis.

Coutu was killed in Laval in July 2009 and Denis was killed in Joliette in May 2010.

If convicted on the murder charges, the three men could face life in prison.

Denis, Lefebvre and Pomerleau were arrested in 2010 after a drug operation bust in Abitibi known as Project Crayfish that led to dozens of arrests. They were reported to have had ties to the Hells Angels.

Quebec’s provincial police say the men are dangerous and have added their names to the province’s 10 most wanted criminals list. They have also notified police departments across Canada and in the United States about the escape.