Ashiqur Rahman, 26, was found guilty in June of manslaughter and aggravated assault in the July 2009 death of seven-week-old Aurora Breakthrough, who suffered broken ribs and internal bleeding, court heard.
Judge Felix Cacchione of Nova Scotia Supreme Court said the former computer science student didn't seem to fully realize the damage he was causing when he slapped, shook and tossed Aurora on five occasions after he grew increasingly frustrated with a series of business failures and the child's cries.
"I'm not satisfied that the evidence established a systemic course of violence," Cacchione said. "Rather I would characterize the incidents as arising from a loss of control due to spontaneous frustration caused by immaturity and inexperience regarding parenting needs of a young infant."
Cacchione said Rahman became so consumed by his desire to become a successful entrepreneur that it outweighed his child's welfare.
"This desire was so strong that it even affected and clouded his ability to be compassionate, caring and considerate of others," Cacchione said.
"In my view this also affected his ability to recognize the danger of the infliction of force on a young infant."
During the trial, physicians testified that Aurora suffered brain tissue tears, bleeding behind her left eye and had 27 rib fractures at the time of her death.
But Cacchione said these injuries weren't visible and hadn't been detected by a medical clinic prior to the girl's death.
"It takes very little force to cause considerable damage to a young infant," he said. "I'm not convinced that Mr. Rahman appreciated this at the time of the offences. I'm not sure he appreciates this to this day."
Prior to sentencing, Rahman said he was innocent.
"I have been and always will be sorry for failing to save my daughter," he said.
"But I tried my best to save her after I learned about her unwellness for the first time. ... I can only take responsibility of my actions, and so I am maintaining my innocence."
During the trial, the defence argued a congenital heart defect played a role in Aurora's death, and Rahman said he called 911 on the day she stopped breathing. But the judge said he accepted medical testimony that the baby died from blunt force trauma to the head.
Rahman met the child's mother, Jane Gomes, while the two were computer science students at Acadia University in Wolfville, N.S., in 2008. The couple started a relationship and moved in together in Wolfville. They later moved to Halifax, where Gomes gave birth to Aurora in June 2009.
Gomes testified against her former boyfriend, saying she saw him slap and hit Aurora in the weeks before she died. In exchange for her testimony, Gomes received a conditional discharge with six months probation for failing to provide the necessities of life.
The mother wasn't in court on Tuesday, but prosecutor Denise Smith read a victim impact statement in court on her behalf.
"I have dreams about (Aurora) very often, mostly happy and a few frightening ones," Smith said.
"Then I wake up to the reality. She is dead. ... There is nothing to be hopeful for.
"Words cannot express how it feels when I think of my grave mistake of trusting Ashiqur with Aurora and the pain she endured in that little life because of that mistake."
Rahman's sentence will be reduced by two years and three months — double the jail time Rahman served prior to trial, Cacchione ruled.
Smith had argued for a prison term of 10 to 15 years. She said outside court she would not appeal Cacchione's decision, saying it was within the range of acceptable sentences.
Defence lawyer Donald Murray had argued for a prison sentence of five to six years. He declined comment as he left the court.