Janitor dips genitals in water bottle, gives woman STD

There are two other ways besides the “dick in the water bottle” theory that these two people can have the same STD. One is that they had sex and the other is that it’s coincidence (I suppose modern lab analysis can probably connect two infections by specific strain/genome if that was done but that’s probably expensive).

There is video evidence of the "indecent assault" that he is being charged with. If he tests positive for the STD and she now has it, yes there's a defense argument that could be made, but barring any evidence of a prior relationship between her and the janitor (which seems unlikely at this point), it would fail and he would also be convicted of the aggravated assault with a deadly weapon.

Genome evidence probably not necessary with evidence or with a distinct lack of evidence of a prior relationship between the two.

Further, it probably doesn't matter if she got the STD from him or not. There is clear evidence that "aggravated assault with a deadly weapon" occurred, as having video that shows he put his STD-infected genitals in contact with her water bottle is already proof that the assault with a deadly weapon occurred, whether or not the assault was successful.

If I attack you with a knife but don't manage to cut you, did assault with a deadly weapon not occur?

The prosecution rests, your honor.