@Bix
There's no rule someone out on bail HAS to appear at their own criminal trial, as long as they haven't actually fled. The prosecution just has to give them the opportunity to face their accusers. But people do get tried in absentia.

If the defendant doesn't show up ... well, given that the jurors are asked to put their lives on hold for weeks to hear the testimony, I can see how they would find it difficult not to let the defendant's lack of concern influence their judgment.