BALTIMORE (AP) — Authorities say a man they say is a serial rapist has been sentenced to 30 years in prison.

The Baltimore City State’s Attorney’s Office says 37-year-old Nelson Bernard Clifford was sentenced Thursday to 31 years and 6 months for sexual assault and theft. Clifford had previously won acquittals in four separate sexual assault cases after he claimed the attacks were consensual. He was convicted May 8 of a third-degree sex offense and theft in a 2007 after attacking a woman shortly after serving nearly 10 years for an earlier sexual assault.

Authorities say Clifford’s history of predatory behavior started when he was 18. He has since been charged in multiple cases with first- and second-degree rape and sex offenses.

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