The Navajo were especially valued by the military because they could be used as code talkers and translators
He was not informed fo his right to consult with an attorney before and or during an interrogation, and he was not informed of his right not to self incriminate. Nor was he informed of his right to remain silent. Basically, the police didn't even read him his Miranda rights.
The framers of the constitution understood that free speech/expression were imperative rights for citizens to have. This is based on their experience as colonists under British control. When ruled by the British, American colonists were forced to pay taxes that they never voted on or approved.
This sparked outrage among some American citizens, causing them to express their concerns in a public manner. This ability to share their views was the cornerstone of America's ability to declare independence from Great Britain. The framers wanted to make sure that once the colonists had their own country that they would have this right to freedom of expression.