Ridiculous questioning scenes...

Ever notice the lawyers never say a single word while their clients are being questioned in the "box"? Is this some British law where the suspects attorney can't give any advice or say a word whilst the detective I are badgering the suspect? The suspects are crazy to say anything that the cops could twist into something else. I think it's because the actors would then have to be paid "scale" and receive credit on the series, rather than receiving standard pittance paid to "extras"... It's really stupid seeing the "actors" playing the lawyers sitting there mute pretending to take notes and glancing at their clients without making any facial expression. LOL...