"Court weighs whether a prosecutor can use a defendant’s refusal to answer a question" ABAJ April 12  http://www.abajournal.com/news/article/court_weighs_whether_a_prosecutor_can_use_a_defendants_refusal_to/

"Supreme Court to consider if silence can be evidence of guilt" 
Reuters Jan 2013
http://www.reuters.com/article/2013/01/11/us-usa-court-silence-idUSBRE90A13P20130111