Ryan is accused of auto theft. ryan refuses to give information related to his alleged criminal activities because he suspects it will be used to prosecute him. this is

This is "the privilege against self-incrimination".

This is the act of implicating oneself in a wrongdoing or presenting oneself to criminal arraignment. Self-incrimination may happen because of cross examination or might be made deliberately. The Fifth Amendment of the Constitution shields a man from being constrained to implicate oneself.