Since Miranda rights are part of a Federal, constitutional right to not require self-incrimination, I was curious about what you mean, and found this: https://harronlaw.com/blog/miranda-rights-texas/
"No discussion of Texas Miranda laws is complete without mentioning the 2013 case Salinas v. Texas. In this case, the Supreme Court said that you must affirmatively invoke your right to remain silent, or it doesn’t count. It’s not enough just to shuffle your feet and look away."
Edit: reading a bit more about it, I don't think this specific case amounts to a law against being silent or one that is specific to Texas. This was a Supreme Court case, and the issue is the defendant wasn't under arrest and wasn't Mirandized and was already talking to police when he went "silent".
"Question: Does the Fifth Amendment's Self-Incrimination Clause protects a defendant's refusal to answer questions asked by law enforcement before he has been arrested or read his Miranda rights?"
Conclusion: No, by 5-4 decision.
What this means is, if you haven't been arrested, then you do have to say out loud something like "I'm exercising my right to remain silent." As far as I can tell this is true in all US states. Once arrested you still presumably have the right to literally remain silent, even in Texas, under the Fifth Amendment.
Is this the one you were thinking of, or is there some other law or case you're thinking of?
"No discussion of Texas Miranda laws is complete without mentioning the 2013 case Salinas v. Texas. In this case, the Supreme Court said that you must affirmatively invoke your right to remain silent, or it doesn’t count. It’s not enough just to shuffle your feet and look away."
Edit: reading a bit more about it, I don't think this specific case amounts to a law against being silent or one that is specific to Texas. This was a Supreme Court case, and the issue is the defendant wasn't under arrest and wasn't Mirandized and was already talking to police when he went "silent".
https://www.oyez.org/cases/2012/12-246
"Question: Does the Fifth Amendment's Self-Incrimination Clause protects a defendant's refusal to answer questions asked by law enforcement before he has been arrested or read his Miranda rights?"
Conclusion: No, by 5-4 decision.
What this means is, if you haven't been arrested, then you do have to say out loud something like "I'm exercising my right to remain silent." As far as I can tell this is true in all US states. Once arrested you still presumably have the right to literally remain silent, even in Texas, under the Fifth Amendment.
Is this the one you were thinking of, or is there some other law or case you're thinking of?