The federal government says it will introduce legislation to make it harder for mentally ill criminals to be let out of custody, following the conditional release of a former doctor who was found not criminally responsible for killing his two children.

The statement comes the day after Guy Turcotte was granted conditional release from Montreal's Pinel Institute, a psychiatric facility, and is the second time in three weeks that the federal government has made an announcement of its intention to change the law.

Federal Heritage Minister James Moore and Conservative Senator Pierre-Hugues Boisvenu said at a Thursday news conference that the new legislation could be adopted in 2013.

Isabelle Gaston, Turcotte's ex-wife, said she was nervous about Turcotte's pending release and fears he could come after her.

Moore said Turcotte's release is "unacceptable." He said the new law would aim to better protect victims and those affected by crimes in cases where the perpetrator is found not criminally responsible.

"We believe that Isabelle Gaston does not deserve to live in fear of her children's killer and neither do victims of similar crimes across Canada," said Moore.

He mentioned the cases of Allan Schoenborn in British Columbia, who killed his three children, and Vince Li, who beheaded a passenger on a Greyhound bus in Manitoba in 2009.

Moore said those affected by such crimes should be able to give impact statements and be consulted before the courts grant conditional releases.

The proposed legislation will need to be drafted while taking into account the different provinces' mental health review boards. It might also involve setting longer time periods during which a person must remain in the mental health system before release, said Moore.

Turcotte is set to be released Thursday.

On Wednesday, a Quebec Mental Health Assessment Commission found that Turcotte had made enough progress to be released.

He was already being allowed out of the institution several times a week on day passes.

Turcotte admitted to killing his children, Olivier, 5, and Anne-Sophie, 3, but had denied intent. In 2011, a jury found him not criminally responsible for their deaths.

Journalists given cease and desist order

Journalists waiting outside the institution where Turcotte was being held received a cease and desist order from the Pinel Institute, forcing them to keep away from the entrance.

The letter penned by lawyers of the hospital states that media presence "causes an important and serious prejudice for all of the personnel and staff and all of the patients hospitalized or treated."

Former cardiologist must stay away from ex-wife

Gaston said she is concerned for her safety despite release conditions imposed on her ex-husband.

"I'm nervous," she said. "There's no policeman that will follow him every day. You know, courtrooms are sometimes full of people that broke their conditions, so I'm just hoping that he's sincere in what he says — that he won't have anything to do with me and he's not mad at me anymore."

Gaston, who was separated from Turcotte at the time of the killings, has maintained she didn't believe her husband killed her children because he was mentally ill, but rather that it was done out of revenge.

One of the conditions of Turcotte's release is having no contact with Gaston or her family, and he must stay at least 500 metres away from her at all times.

"I hope never to meet him because I don't know how I would react and how he would react with me," Gaston said in an interview with CBC Montreal's Daybreak.

"Five hundred metres is not very far."

Gaston said she understands the commission's decision to grant Turcotte release and said, given the charter rights the committee must uphold, Wednesday's decision was the best she could have hoped for.

"People could be mad about their decision, but they had their hands tied," she said.

"The rules say that if you think that a person may be dangerous, that's not a reason to keep him. In the charter of human rights, you cannot bypass his right to be free."

Gaston said she would continue to fight for changes in the way similar cases are handled by the justice system.

Unless Turcotte fails to keep the peace and adhere to his conditions, his case will not be reviewed for another year.