The actor was among activists who interrupted a university board meeting to demand an end to cruel and deadly brain experiments on cats.
Reports suggest Cromwell held up graphic photos depicting the scientific decapitation of a cat named Double Trouble and yelled, "Shame on Uw for mutilating and killing cats!"
Campus police escorted the Oscar nominee and members of People for the Ethical Treatment of Animals (Peta) off the premises on 7 February (13), but he will not face charges after paying a $100 (£65) fine.
Cromwell says, "It's not the cats who need their heads tested but the Uw board of regents, which allows these hideously cruel experiments. Our protest was lively enough to alert millions of people worldwide that cats are having their heads drilled into, being deafened, and then being decapitated, and Peta will keep protesting until it stops."