Public Safety Minister Vic Toews announced Thursday the government is closing three penal institutions — the Leclerc Institution in Laval, Que., Kingston Penitentiary in Ontario, and the Regional Treatment Centre at Kingston Penitentiary, which was the only federal correctional psychiatric facility in Ontario. Once they're closed in two years, the federal government will save $120 million a year. Here are four questions to ask about the closures.

Why Kingston?

Kingston Penitentiary is the oldest in Canada — older than Canada itself. It was built in 1835, although the Union of Canadian Correctional Officers points out it's had millions of dollars in renovations to update it. But one theory put forward by a panellist on CBC The National's At Issue panel is that the decision is political.

"I think, to put it really simply, that they're moving jobs from Liberal or opposition areas to Conservative, good Conservative areas. And they're adding cells, and where those cells are going to be is going to be really interesting," Chantal Hébert said.

"You're getting rid of 1,000 spaces. You are going to be reallocating them. Some of those expansions are taking place in Vic Toews' own riding."

Some of the new spaces will be going to Stony Mountain Institution, just outside Winnipeg, which was built in 1877. New Brunswick's Dorchester Institution is also "19th century," as Toews referred to Kingston Penitentiary, having been built in 1880.

Hébert also pointed out the federal government isn't consulting the provinces.

Where will inmates in the Regional Treatment Centre go?

There are only five corrections psychiatric treatment centres in the country, says Howard Sapers, Canada's correctional investigator. When Kingston's Regional Treatment Centre closes in two years, that will be four treatment centres with less than 700 beds — and they're all full. Kingston's RTC houses 140 inmates.

"There simply is no place to put them. Even if you wanted to go to inter-regional transfers, the other four treatment centres don't have the capacity to absorb this population," Sapers said.

"Clearly there is a need, a well-established need for 150 of these treatment beds in the Ontario region and unfortunately, sadly, the number of mentally-ill offenders is growing, not shrinking."

Jason Godin, a spokesman for the corrections union, says it will be a challenge to integrate prisoners from Kingston and Leclerc into other institutions.

"We have so many problems with gangs, organized crime. We have all kinds of mental health cases, which, you can't just assimilate those groups into other populations, into other institutions. It's going to create a lot of problems," he said.

Where will they put the prisoners?

The closures mean the government is moving 1,000 prisoners. They're expected to build 2,700 new spaces, but Justin Piché, who studies penal policy and prison construction at Memorial University in St. John's, Nfld., has said they won't have enough room for the existing maximum security prisoners.

Numbers provided to CBC News by Correctional Services Canada Friday show little extra room in the system. As of March, 2012, there are 14,916 inmates in federal institutions across the country. Total capacity in the system is only about 200 more than that: 15,115.

Ontario's correctional services minister said Thursday she doesn't think the decision has been properly thought through.

"We're already housing some of their inmates because they don't have space in their federal penitentiaries and now they're closing one of their largest ones, so I don't understand their decision," said Madeleine Meilleur.

"With C-10, there'll be more people that are being put in jail so we'll need more beds so it's going to put pressure to the province because we are already housing some of their clients."

Meilleur has previously said the omnibus federal crime bill will cost Ontario more than $1 billion in increased police and court costs, and estimates it could add another 1,500 inmates to the provincial system by 2016.

Carissima Mathen, a law professor at the University of Ottawa, says the closures raise a big capacity issue, and the government owes Canadians "very clear explanations" about how they're going to work.

"In the context of a prison population, you really want to make sure you've got all your ducks in a row… It's not like closing any other institution in society."

How will new mandatory minimum sentences add to the burden?

Toews says the influx of prisoners predicted by his department after the government brought in the truth in sentencing act never materialized. That law limited credit for time served, putting people in prison for longer, and was expected to be an extra burden on the system. The bill became law on Oct. 22, 2009.

But it takes months or years for serious crimes to make their way through the prison system. There's a backlog in the court system, meaning progress is slow. And the government's new mandatory minimum sentencing provisions, which became law March 13, 2012, still haven't taken effect.

"Unfortunately, gathering this kind of data, it does take time and it's difficult to do systemically because even though they're federal prisoners, it's all happening in provincial courts, so you've got tonnes of jurisdictions to deal with," said Mathen.

CSC would have intake information, she says, so Toews could be privy to numbers that aren't public yet.

"But even so, I would think it would take a while."

With files from Alison Crawford and The Canadian Press