For decades, the police in Shelby County, Ind., could not identify the man who broke into houses at night, armed with a knife or a gun, woke his victims, and then bound and sexually tortured them. He often disguised himself in a bulky coat and covered his face with a ski mask or leggings.

Then, in 2020, 35 years after his last known assault in the county, investigators were finally able to identify the attacker as Steven Ray Hessler, and arrest him. The breakthrough came, prosecutors said, when DNA extracted from the envelope of a water bill that Mr. Hessler had licked matched DNA that had been left at the scene of his last known crime in the county, on Aug. 17, 1985.

On Friday, Mr. Hessler, 59, was sentenced to 650 years in prison. The sentence came a month after a jury convicted Mr. Hessler of two counts of rape, six counts of unlawful deviate conduct, seven counts of burglary resulting in bodily injury, three counts of criminal deviate conduct and one count of robbery.

James B. Landwerlen, the prosecutor in Shelby County, southeast of Indianapolis, said that from Aug. 14, 1982, to Aug. 17, 1985, Mr. Hessler brutally assaulted 10 victims: seven women, a 16-year-old girl, and two men, including a former Marine whom he had handcuffed, hogtied and beat with a gun, leaving him in a coma for months.