Officials in Maryland say a man knowingly spread HIV to four women he met on dating sites and apps.

WBAL-TV reports 34-year-old Rudolph Jericho Smith, of Frederick, Maryland, was charged with first-degree assault and reckless endangerment after police conducted a 21-month investigation into his alleged crimes.

Smith also faces counts of knowingly transferring or attempting to transfer HIV to another person, which is classified as a misdemeanor under Maryland's general health law.

Frederick police Lt. Kirk Henneberry told the local news station that detectives began their investigation after several women reported Smith infected them with HIV.

Once Smith's blood was tested and determined to be HIV positive, Smith continued to meet women on dating sites. After meeting the women, Smith had unprotected sex with them without disclosing his HIV status.

Although detectives tested Smith’s blood in 2017, they say he was aware of his diagnosis since 2014.

As part of their case against Smith, prosecutors and police had to prove beyond a reasonable doubt he knew he was HIV-positive before they could file any charges, Frederick County State's Attorney Charlie Smith told WUSA9 in reference to the lengthy investigation time.

Smith is currently being held on a $100,000 bail at the Frederick County Adult Detention Center.

Anyone who may have had a sexual relationship with Smith around or after July of 2017 is urged to contact Frederick police officers at 301-600-TIPS (8477), text 240-674-8477 or email them at FPDcrimetip@frederickmdpolice.org.