Curiosity's Search for Organics

I do not understand why we would attempt such a massive effort to deposit a rover on Mars without the ability to identify life. Even if the mission is 100% success, we will still not have any proof that we are not alone in the universe. I have to believe that the ability to detect life is present on the rover and NASA is simply not making that public.

That way, when the rover does find life, they can easily cover it up. It is too risky for the general public to be aware of extraterrestrial life.