A Guelph man killed his seven-week-old son as the boy’s mother slept in the next room, court heard Monday.

Bobby Gregoire, 34, was charged with second-degree murder in June 2014 – nearly two years after the infant was found without vital signs in a home on Julia Drive.

Emergency workers were able to revive the boy, but he died the next day.

Court documents show that he had suffered a severe head injury after being struck, and medical examiners found evidence he had been shaken.

Monday, Gregoire pleaded guilty to manslaughter and apologized to the court for his behaviour.

“I take full responsibility for my actions,” he said.

“I don’t know why I did what I did.”

Also in court Monday was the boy’s mother, who tearfully explained the impact Chase’s death has had on her life.

Though an interpreter, Katrina Swartz said that she now suffers from sleeplessness, depression and suicidal thoughts.

“I’m constantly crying inside,” she said.

The Crown recommended an eight-year sentence for Gregoire, citing the fact Swartz was left asleep after the boy was injured.

“He could have and should have woken her,” Crown attorney Janine Hodgins said.

Gregoire’s lawyer has suggested a sentence of four or five years.

A judge is expected to decide his fate later this month.