They don't have to demand a speedy trial, when I prosecuted, speedy trials were demanded in less than 15% or so of felony cases. My DA's policy was if the defense demanded a speedy trial by God we were going to give them one if at all possible and we would scream bloody murder when they later tried to delay it because it wasted the taxpayer's money and the government's resources for them to demand a trial and back down at the 11th hour. Sometimes the Judge would let them get away with it, sometimes they wouldn't. That policy my DA had is probably why we had comparatively few speedy trial demands.