01/09/2012 02:19 EST | Updated 03/10/2012 05:12 EST

Slain woman's husband hangs himself in jail

A Quebec man has been found dead at a Montreal detention centre, one month after his arrest on first-degree murder charges in the death of his wife, Diane Grégoire.

Provincial police confirm they found Paul Laplante, 54, unconscious in his cell Monday morning at the Rivière-des-Prairies detention centre, in Montreal's east end.

Guards found he had hanged himself when they carried out their second roll call between 10:30 and 11:45 a.m.

Prison workers tried to resuscitate Laplante with CPR, but he was confirmed dead around noon.

Laplante was arrested in December and charged with first-degree murder after the remains of his wife were found in the fall.

Grégoire, 51, had not been seen since 2008.

Laplante was to remain in detention until Feb. 20, his next scheduled court date.

Authorities at the detention centre are investigating his death.

Grégoire case spanned 4 years

Police had few leads to work with after Grégoire's 2008 disappearance, despite a public campaign.

She was reportedly last seen by her husband on Jan. 31, 2008, in a mall parking lot in Saint-Bruno, on Montreal's South Shore.

Laplante had told police he dropped his wife off at the mall in the morning, but she didn't show up at a scheduled time later in the day.

Investigators searched the mall and surrounding area on several occasions.

In September 2011, police announced they were resuming their search for Grégoire and said they believed she had been killed.

Forensic investigators launched an intensive, month-long search of a pig farm in St-Valérien-de-Milton, Que., east of Montreal's South Shore.

In November 2011, police identified bone fragments found in a wooded area less than 100 kilometres away as belonging to Grégoire.

Laplante was arrested three weeks later and charged with first-degree murder.

His suicide comes as no surprise to people who have followed the case.

"We thought this could happen," said Anita Fleury, a member of a citizens' support committee formed after Grégoire's disappearance.

"Police seemed to have really good evidence before they arrested him."

Laplante once served as mayor of Saint-Liboire, a small municipality in Montérégie.