I'm looking for a word which defines the act of "making an offence look less severe". However, this can be done rightfully (because an offence might in reality be excusable because of unfavorable circumstances) or unrightfully (because there are no excuses for the offence, but the offender is trying to get away with it anyway, so this word is most likely pejorative).
Are there different words to describe each situation above, that I could use in everyday language, without sounding too formal?
What about 'extenuate' and 'palliate'? What other words are there, that have more exact definitions like these two?