Not everyone knows they have these rights. I remember in high school being told repeatedly that I had no rights as a minor. We never actually learned about our constitutional rights; I had to find those out on my own.

Also, people have a natural tendency toward defending themselves after being accused. Being read your rights is a reminder, in the heat of the moment, that no, you don't have to talk and you have the right not to. And your right to remain silent is important even if you're not guilty (maybe especially!). Dont Talk to Police: http://www.youtube.com/watch?v=6wXkI4t7nuc

Once he resumed consciousness he has a right to remain silent but the "public safety" exemption that the Supreme Court inserted to the Miranda rule in 1984 was changed even further by Obama in 2011 that allows the government to question a suspect for 48-hours. Is that a greased, slippery, slope or what?

References:

[1] Think Progress - http://goo.gl/DPV6L [2] Wall Street Journal - http://goo.gl/fEPnO

Yeah, this article and most comments seem pretty ridiculous.

Yeah, let's just assume he knows all of his rights. Come on! It's on TV all the time and stuff. No reason to even bring them up.

Now where did you buy those pressure cookers, hmm?

Individually, no. But the Miranda process isn't about the individual alone, it's about the whole system of law.

But in this case, certainly they should ensure he doesn't die due to lack of medical attention while they attempt to read him his Miranda rights.