I don’t know how the procedere would be executed, but I imagine that police could have the phone present during an interrogation and try to nlock it there (possibly by making you to look at the phone to unlock it, if the phone has been set up to unlock this way). Once unlocked, it would be sufficient to have a peek into the camera roll or messages, until the phone locks again. I don’t know about the law, but I can imagine that if a police officer had a look into your phone, even briefly, it may be held against the one who is being interrogated.
If there is life out there, it would be rather unspectular. It would exist in the form of microbes, probably not even visible by the human eye. There are theories that suggest that there is a high chance of life on Enceladus.
One of the reasons that life could develop into complexity on Earth is that it could develop over the course of millions of years relatively undisturbed. There were no outside events like supernovae that swept Earth out of exsistence. The Primordial Soup could be cooked long enough to result in complex and intelligent life forms. Other places in the universe probaply have not that advantage, so that the development of life didn’t come that far yet.
I suspect that there is a higher chance that life in other places of the universe will be tainted by humanity than the other way round.