Christopher Alexander Falconer has been found guilty of first-degree murder in the death of Amber Kirwan, ending a case that has gripped Nova Scotia since the teenager's disappearance and the subsequent investigation into her slaying.

Nova Scotia Supreme Court Judge Nick Scaravelli sentenced Falconer, 31, to life in prison with no chance of parole for 25 years after the 12 members of the jury in Pictou delivered their verdict on Tuesday afternoon.

The jury's deliberations lasted for 7½ hours.

Marjorie Kirwan, Amber's mother, began sobbing as the verdict was read. She later said she was "very" pleased with the verdict but gave no other comment.

The 19-year-old victim was last seen alive by friends after leaving Dooly's pool hall in downtown New Glasgow in the early hours of Oct. 9, 2011. Her remains were found about a month later in a shallow grave in Heathbell in Pictou County.

Crown attorney Bill Gorman said Kirwan's family will never fully recover from her death.

Amber Kirwan, 19, disappeared in October 2011. Her remains were found a month after her disappearance. (Facebook)

"Their sense of relief, I believe, was palpable, but this is a tragedy that I don't think they'll ever get past," he told reporters on Tuesday.

"Justice was done. The jury carefully and thoughtfully considered. They would have deliberated for the better part of a day and they got our message and they made their finding."

The trial lasted nearly three weeks after Falconer pleaded not guilty to first-degree murder.

The Crown presented witness testimony and text messages that traced Falconer's movements from the time Kirwan was last seen. Her body and clothes were found in a shallow grave close to the home of Falconer's stepsister and there was a bloody tank top found in his car, with both his and Kirwan's DNA on it.

The medical examiner testified Kirwan bled to death after being stabbed at least 10 times, mostly on her neck and upper back. One stab wound went through her heart, court heard. There was also evidence Kirwan "vigorously" defended herself against her attacker, despite high levels of codeine in her system.

Defence lawyer Mike Taylor said he wasn't shocked by the verdict.

"The decision they made can't come as a complete surprise to anybody. Obviously, I would have preferred for Mr. Falconer that it was different, but the evidence was there and I can see them reaching the conclusion they reached," he said outside the courtroom.

"He's disappointed, obviously. I think he was thinking that there was a decent chance of acquittal because of the time that they were taking."

Taylor said at this stage, he doesn't plan to file an appeal.

"We'll look at things in the days to come, but it's a little fresh right now to even consider an appeal. An appeal of a jury is extremely difficult," he said.

2nd murder conviction for Falconer

This is Falconer's second murder conviction. He pleaded guilty to second-degree murder in 1998 and was sentenced to life in prison. He and another teenager killed cab driver Robert Leblanc, then went joyriding in his taxi.

That killing happened on Heathbell Road, the same road where Kirwan's body was discovered.

Falconer was released after serving more than 10 years in prison for Leblanc's murder.

Police suspected Falconer early in their investigation of Kirwan's disappearance. That suspicion was enough to have Falconer's parole revoked in February 2012. He was returned to prison until he was formally charged three months later with Kirwan's murder.