PETA v. SeaWorld

I am writing this in response to a news article I've read that PETA brought an action on behalf of five orcas--- Tilikum, Katina, Kasatka, Corky and Ulises, against the two branches of SeaWorld from Orlando, Florida and San Diego, California.

The action was brought on the ground of slavery, and PETA argued that the orcas should have the same constitutional rights as humans.

As much as I love animals, and I can understand PETA taking an action. However, I do believe they have missed the fact that Tilikum has been linked to three deaths, e.g. in February 2010, he drowned his trainer in front of spectators. I just have been thinking, if PETA is indeed successful in doing so, that the orcas are entitled to the same constitutional rights as humans, then Tilikum can be prosecuted for murder/manslaughter...This in turn will be very ridiculous, as how on earth can you establish the mens rea of an animal?? Hire what? A special translator like Dr. Doolittle?