A St. John's man accused of shaking his own baby was taken to a cell Tuesday after he was found guilty of aggravated assault.

Colin Matchim, 25, was charged in 2009 after his daughter, August, was brought to hospital with what proved to be serious injuries.

Matchim had denied that he hurt his daughter even though the Crown presented videotape of a police interview in which he admitted to shaking the girl, although not violently.

Justice Wayne Dymond rejected Matchim's defence, which included a suggestion that the girl's mother, Kate Coombs, was actually responsible for the harm that came to August.

Dymond concluded that Matchim's words in an emotional texting exchange were a partial confession and corroborated other confessions he made to the police.

"just know that it was an accident ok she was holding her breath and she wouldnt let go and i panniked," Matchim wrote in a lengthy exchange with Coombs, who told her estranged partner that she was furious and would not speak to him.

Following the exchange, Matchim went to the police and told investigators what happened. Matchim's lawyer later fought having that tape admitted.

Dymond cited medical evidence that showed the girl, who was three and a half months old at the time, has sustained permanent brain damage.

More than two years later, she still has paralysis on the right side of her body. At trial, one doctor testified that he was surprised she even lived.

Until he was taken into custody, Matchim had been released on bail.

In remanding Matchim, Dymond noted that there have been concerns about his stability, noting that Matchim had once taken pills and called 911, and had suggested to Coombs during the texting exchange that he had no reason to live.

Dymond said that for the safety of Coombs, their daughter and Matchim himself, Matchim needed to be brought into custody.

Matchim has since been charged with breaching court orders to stay away from Coombs.

A sentencing hearing is scheduled for July. The maximum prison sentence for aggravated assault is 14 years.