Two women took the witness stand Tuesday to describe having sexual contact with a man they say knowingly exposed them to HIV.

One, a 21-year-old Kansas University student, said she met 29-year-old Robert W. Richardson II through KU’s Society of Open-Minded Atheists and Agnostics. She said she had unprotected sex with him three times in early January and didn’t learn until afterward that he was HIV-positive.

“I assumed if someone has HIV, they wouldn’t have unprotected sex with people,” she said at a hearing on Richardson’s case in Douglas County District Court.

A second victim, age 40, testified she met Richardson in mid-January through an online dating site, OkCupid.com, and that she learned he was HIV-positive shortly after meeting him.

She testified she had sex with him Jan. 20 on the condition that he wear a condom. But during their encounter, she said, he removed the condom without her noticing.

When she later noticed the condom was gone, she said, the encounter stopped.

After hearing evidence, Judge Stephen Six ruled there was enough evidence to try Richardson for exposing each of the women to HIV, a low-level felony. As the hearing ended, deputies arrested Richardson on a new charge involving a third victim, but details of that case weren’t available Tuesday.

Previously, defense attorney Thomas Johnson had said he expected more charges to be filed.

If the cases go to trial, they’re likely to hinge on Richardson’s mind-set at the time of the encounters. Prosecutors must prove three things beyond a reasonable doubt: that Richardson knew he had the virus, that he had sex with the women and that he intended to expose them to it.

Johnson pointed out that the odds of the women actually contracting the virus were low. Both have tested negative for HIV.

“I know that my chance of getting it is very low, but any chance is still a crime,” the 21-year-old woman said.

“Isn’t that for a jury to determine?” Johnson asked her.