Found the quote:

The complexity of modern federal criminal law, codified in several thousand sections of the United States Code and the virtually infinite variety of factual circumstances that might trigger an investigation into a possible violation of the law, make it difficult for anyone to know, in advance, just what particular set of statements might later appear (to a prosecutor) to be relevant to some such investigation.

Stephen G. Breyer, You Have the Right to Remain Innocent

It's used around 4:40 in the Don't Take To The Police video.