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]
(..) when he worked at S.I.P. - What? - He tried to break it off, you got upset, and you made up this whole sexual assault story to get him fired. - What?! -Says he came to your apartment to try and straighten things out, but your security people (..)2018 Fifty Shades Freed