Claude Letourneau had already pleaded guilty to 32 counts of theft, assault with a weapon causing harm, and assault with a weapon.
Crown prosecutor Emilie Baril-Cote says Quebec court Judge Conrad Chapdelaine took into consideration the joint recommendation of lawyers as well as Letourneau's past criminal file.
She called Thursday's sentence fair.
"The judge believed the sentence we suggested was appropriate considering the state of terror that the city of Sherbrooke lived in during the time the blood was put into the garments," said Baril-Cote.
She said the judge also considered the fact that several people had to undergo medical treatment after they were pricked with the needles.
The first needle was found in August 2011 in Sherbrooke, about 150 kilometres east of Montreal.
Letourneau was arrested last June.