MONCTON, N.B. -- Convicted cop killer Justin Bourque plans to appeal his life sentence with a new lawyer.

Joelle Roy, a lawyer with the criminal law firm Gagne & Roy in Saint-Jerome, Que., confirmed Saturday she is now representing Bourque and is working on an appeal.

Bourque was convicted of killing constables Dave Ross, 32, Fabrice Gevaudan, 45, and Doug Larche, 40.

Constables Eric Dubois and Darlene Goguen were also injured in the shooting rampage through north-end Moncton, N.B., in June 2014.

Bourque was sentenced to life in prison with no eligibility for parole for 75 years last October after pleading guilty to three counts of first-degree murder and two counts of attempted murder.

Roy would not go into details of the planned appeal, but said when she's ready, she will be open to discuss it further.

"There's a lot to check and I don't want to miss anything," she said.

"I want to turn over every rock."

Roy declined to comment on the timeline for the appeal, but did say it could be a fairly long time.

"This is a really big case ... and there's a lot to check," she said. "You don't do it in four months."

Bourque's sentence was the harshest Canada has seen since the last state-sanctioned executions in 1962.

It was the first time a 75-year sentence was given under a section of the Criminal Code that was amended in 2011. The amendment gives the judge the option of extending parole eligibility in the case of multiple murders.

Members of the law community have expressed concerns with Bourque's sentence in the past.

In March, Quebec lawyer Jean-Claude Hebert was critical of how Bourque's lawyer handled the case and said there are numerous possible grounds for an appeal.

Hebert said New Brunswick's law society has a social obligation to help people like Bourque and suggested a lawyer be appointed to try to persuade Bourque to get on board with an appeal.

The society said it wouldn't appoint a lawyer to look into whether to appeal Bourque's unprecedented sentence, noting that the group does not get involved in individual cases.

Peter Sankoff, a professor of law at the University of Alberta, said in March the length of the sentence has been a topic of discussion among some lawyers across Canada since it was imposed in October 2014.