The pair were given two-for-one credit for time served. They've been in custody nearly five years. Lowenberger died in 2008.
“We didn’t feel as though two convicted killers should have been walking out of court,” said Crown lawyer Chris White.
“There will be serious consideration of a sentence appeal,” he added.
Officers had to escort members of the Lowenberger family out of the court room. One of Lowenbergers supporters yelled "No justice!" as she angrily left the courthouse.
“I think the judge balanced all the factors and all the facts very well,” said Lavallee’s defense lawyer Jeff Deagle. Earlier in the day, an application for a mistrial by Zerr and Lavalle's defense was dismissed by the judge, who said an appeal court could decide.
The application was made because the lawyers said the jury wasn't properly instructed and their clients could have been acquitted based on self defence.
The Crown asked for 15 years for Zerr and 12 for Lavallee.