Mark Edward Grant is planning to appeal his conviction in connection to the death of Winnipeg schoolgirl Candace Derksen.
"You can count on it," Grant's defence lawyer, Saul Simmonds, told CBC News on Monday.
He said the appeal can only happen after the sentencing process, set for next month, has been completed.
"The jury has left [Grant] very disappointed in their verdict. Obviously, from our perspective, the matter will have to go further," Simmonds said.
After an emotional and at times complex five-week trial, a jury weighed the evidence for two days before convicting Grant, 47, of second-degree murder on Friday evening.
He faced a first-degree murder charge, but the seven-man, five-woman jury found him not guilty in favor of convicting him of the lesser offence.
Derksen was found hog-tied and frozen to death on the dirt floor of a rarely-used supply shed in a brickyard about 500 metres from her family home on Jan. 13, 1985.
She vanished off the street while walking home from school on Nov. 30, 1984. Her disappearance triggered a massive community search, and struck fear into the hearts of many that a predator was on the loose.
Derksen's death remained a public mystery until May 2007 when police came forward with new forensic evidence linking Grant to the murder scene.
Jurors did not make a recommendation to the court about when he may be eligible for parole.
The second-degree murder conviction carries with it no chance of parole for a minimum of 10 years, but the court could elect to raise that as high as 25 years.