As with Mars, water has been confirmed to exist on Pluto.
That means there is every reason to speculate that life could have existed on those two planets and that it still does. Given that the life force is no slouch when it comes to being opportunistic, the odds are that entities from Mars and Pluto have made their way to planet earth.
Years ago, scientist Stephen Hawking had warned us to be circumspect when we encountered aliens. More recently, his word of caution has turned darker. He is putting out there the analogy of Christopher Columbus. After the white man arrived in America, the natives were destroyed. Aliens from Mars and Pluto could exterminate us.
The legal system has to come to grips with this, just as it did with issues such as privacy and libel in social media.
For example, an unknown flying object lands on our lawn. Creatures exit and head toward our door. Do we have to wait to find out if they came in peace or can we immediately use lethal force?
A space alien has entered my brain. What legal measures will there be to have it evicted?
More and more creatures from Pluto want to be admitted as members to our country club. On what grounds can we legally keep them out?