A 42-year-old Fort Worth man has been sentenced to 15 years in prison for having unprotected sex with a woman and infecting her with HIV, officials said.Jimmy Bernard Billingsley pleaded guilty earlier this year to aggravated assault causing serious bodily injury.Billingsley chose to have State District Judge Robb Catalano assess his punishment, according to a news release from the Tarrant County Criminal District Attorney's Office. He faced from probation to 20 years in prison.On Friday, Catalano assessed the 15-year prison term after reviewing a pre-sentence investigation report and hearing testimony from several people, including Billingsley.According to testimony, Billingsley had been intimate on numerous occasions with a woman he met in 2009 while coaching her son's youth football team. In late 2010, the woman learned she was HIV positive and immediately called police.Because Billingsley was the only man with whom she had been intimate, she suspected that he had infected her with the virus after he insisted on having unprotected sex.Billingsley testified that he has had numerous sexual partners since he learned he was HIV positive in 2008, but he didn't warn his partners.The case was handled by prosecutors Joshua Ross, Rebecca McIntire and Kalere Jacob Coleman."This defendant's intentional non-disclosure to numerous sex partners was egregious, dangerous, willful and malicious," Ross said. "He is truly a snake in the grass. His sentence brings some justice to his known victim and provides a measure of protection for so many others."