What three samples from three unnamed people? There's only been one other person, her boyfriend, who's been tested for a match to one sample of semen taken from her that I've heard spoken of on this forum and in the media.
They sampled three other people after preliminary results came back saying there was no match with any member of the team.
Why three people? Because there was semen found in her from three separate people?
I have never heard them say they found semen from only one source. They have said they found one match, not one source.