After a four-month investigation, Lyle Knox Jr., 50, was arrested Monday and charged with exposing others to HIV.
The police report states he did not disclose that he had the virus while he and the woman were together.
According to officials, detectives obtained Knox's medical records after he initially denied having the virus, and it wasn't until his arrest that he admitted he had been HIV-positive for nearly two decades.
According to police, arrests for the charge of exposing someone to a disease that could be deadly is extremely rare in York County.
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HIV is a virus spread through certain body fluids that attacks the body’s immune system and can lead to AIDS.
In South Carolina, it is a crime if someone with HIV knowingly engages in sex with another person without first informing that person of the virus, shares medical needles without informing another person about the virus and sells/donates blood or organs.
Police said Knox was released from jail Tuesday after posting a $6,000 bond.
He faces up to 10 years in prison if convicted.