A retired Catholic priest has been sentence to six months house arrest after pleading guilty to sexually assaulting two Saskatoon boys in 1959 and 1961.

Father William Hodgson Marshall, who also pleaded guilty to 17 counts of indecent assault against former Windsor, Toronto and Sudbury students, was in the Windsor Superior Court of Justice on Monday.

He received a sentence of six months in the community, to be served at the Cardinal Flahiff Basilian Centre in Toronto.

The Crown was seeking a nine to 12 month sentence.

Marshall, 90, addressed the court.

"I didn't really believe I was hurting the kids,” says Marshall. “I certainly didn't think I was a monster."

Defence lawyer Andrew Bradie asked the judge not to re-incarcerate his client, claiming  Marshall had already paid a significant price.

"I said to the judge that I think he's slipping mentally,” says Bradie. “He certainly has a lot of physical difficulties and he is 90 years old with a history of health problems."

About 70 people staged a public demonstration in front of the Windsor courthouse Monday morning.

"I'm very disappointed,” says previous victim Patrick McMahon. “I don't think there was any justice given to the victims who had the courage to come forward from Saskatoon. I can't say I'm surprised."

McMahon says he’s already received what justice the courts were willing to give him in the small sentence he received two years ago.

Marshall admitted in June 2011 to sexually abusing 17 young people and sentenced to two years in prison.

In October, Marshall was qualified for statutory release, serving a total of 16 months in jail.

“People need to know that this is not acceptable justice,” says McMahon. “It is not a deterrent for these types of crimes and it’s certainly not a deterrent for the people who protected him and enabled him to do this for 50 years."

Marshall was a teacher at Windsor's Assumption College and the founding principal of Holy Names high school.