He was accused of 'assault'. = He was charged with 'assault'. = 'Assault' charges were brought against him.
He came 'under assault' for his unusual beliefs. [=he was severely criticized for his unusual beliefs]
He was found guilty of 'sexual assault'. [=the crime of touching someone in an unwanted sexual way]
(..) Just remember to keep talking and don't stop. This is Finnick Odair. And I'm coming to you from District , alive and well. We've survived an assault from the Capitol. But I'm not here to give you recent news. - Why is Finnick doing a propo? - It's a lot more than that. (..)2014 The Hunger Games: Mockingjay - Part 1