Johnson was born in 1947 and lived in London, Ontario. He was a factory worker with no significant record. He climbed the outsides of apartment buildings at night, sometimes several storeys, and entered through balcony doors left open in the summer.
Between 1973 and 1977 he killed seven women: Mary Hicks, twenty; Alice Ralston, forty-two; Eleanor Hartwick; Doris Brown, forty-nine; Diane Beitz, twenty-three; Luella George, twenty-two; and Donna Veldboom, twenty-two. Most were strangled in their beds and some were stabbed. He was called the Balcony Killer and later the Bedroom Strangler in the Ontario press.
He was arrested in 1977 and tried in February 1978. He was found not guilty by reason of insanity, the verdict then available in Canada, and committed to the Oak Ridge maximum-security unit at the Penetanguishene mental health centre.
He has been detained continuously since and has appeared before the Ontario Review Board annually for more than forty years. He has never been released and applications to move him to lower security have been refused. Because there was no conviction there is no judgment, and the account of the killings comes from the psychiatric assessments produced for the trial and the annual board hearings, which are the reason the case is still reported in Ontario at all.