Woolwich Crown Court ruled today that Delroy Grant, 53, had broken into the south London home of an 89-year-old woman in 1992 and then raped her.
They also ruled that he carried out a brutal sex attack on another 81-year-old woman in Warlingham in 1998.
Police apologised for missed chances to stop Grant as they said he was responsible for some of the most “awful and disturbing crimes” in the history of Scotland Yard.
At the start of the trial, Jonathan Laidlaw QC said: “The defendant was targeting the elderly and vulnerable in their homes and during the night.
“That is why he was to become known as the Night Stalker.”
The jury convicted him of assaulting at least 18 victims, but feared he may have attacked more than 500 people.
Grant targeted the elderly, some of his victims were up to 89 years old and were blind, deaf and had either Alzheimer’s or Parkinson’s disease.
He was a skilled burglar and would prise out window panes out of homes to gain entry.
Typically he would remove light bulbs, cut the telephone wires and then wake the terrified victims by shining a torch in their eyes.
Grant would then force his victims to endure humiliating and degrading sexual assaults for a reason that the court described as “impossible to understand”
The police manhunt finally caught up with him in 2009 when they swooped on his car.