Legally, he would.
You can't prosecute with evidence that isn't collected under due process.
Imagine, if you will, a situation where an advanced species experiences some catastrophic event on their home planet. Or will experience it. There are several possible angles, here - Uranus has a very interesting name in Japanese and is a peculiar planet…. But we'll leave that one alone.
Perhaps this species was so advanced that individuals of it could manage planets like home CNC projects. In which case - perhaps they really don't have a home planet but more like a pet project.
So, they settle on Earth in the fallout of whatever it was dooming their project planet. Maybe they lost technology - or perhaps there was some infighting that stranded a group.
As time goes on, they begin resorting to something closer to the reproduction of the animals on Earth, and also begin tinkering with a few of the sapient creatures. Good help is hard to find, after all.
Then shit starts to get a little sideways. Animal rights activists start giving them more knowledge and ideas of freedom. This sows division among the pantheon, as they are literally surrounded by millions of fire-apes, now, and the 'help' starts crunching the math they now have.
You ever wonder why Prometheus was tortured and why the god of scribes (the god of all monotheistic religions) considers him the fucking embodiment of evil - that's why.
Now the gods all have to be careful what toys they leave laying around, lest an ape think it a fun idea to blow up the moon, or something. Because that seems to be a theme.
The gods have been playing games with each other ever since - or their descendants have - going toward the goals of either global slavery or global enlightenment to settle the dispute once and for all.