This is a first-hand account from someone sexually assaulted by Biden (language warning):
https://www.thecut.com/amp/2019/03/an-awkward-kiss-changed-how-i-saw-joe-biden.html
It's past sexual harassment. Sexual harassment is about insinuating, saying things, making advances, etc. Sexual assault is physical, which is exactly what Biden did with smelling hair, inappropriate touching, and unwanted kissing. Regardless of his intentions, if the victim didn't want it, and it happened, then it's assault. It's not in the same degree (as in legal degrees) as penetrative rape, but it's still assault. Pretty much every crime has different degrees of seriousness, but they all get labeled the same way.
The law isn't making an assumption. Biden is literally on camera committing sexual assault, he's been at the focal point of several controversies over it, and it's not like it's exactly hidden. Only this most recent allegation is being swept under the rug.
Based on how Biden conducts himself and the photographic evidence backed up by first-hand accounts, that's what leads me to believe he's probably worse then what's being shown and why nothing would really surprise me if it surfaces. I'm not saying convict him on opinion, but there are more than just opinions that shows he's guilty.