Yes , that is so, but it no explanation is given re the risk of Julene interfering with Joshua's testimony, or Josh interfering with Julene's, or both, or either of those two interfering with anyone else's testimony in regard to Rick and Trent. Considering those two and their determination to keep quiet and lie to police for a whole year, and to the Crime Commission hearings, on many occasions, it isn't improbable that either of them, alone or in concert wouldn't at least have a shot at merely interfering with anyone's testimony against their precious boy.
Which is why it seems plain that there has to be a whole lot more. Incest , for all it's horror, is not on the scale of things as serious as murder, which is the highest level ( apart from treason ) of indictment. And that particular charge , since Tia is deceased , can not be replicated , unless it is thought that Joshua is in danger of being sexually interfered with by Trent.
And Trent's age is another curiosity for being refused bail. The combination of his age, and the charges laid against him, leading to refusal of bail is unusual.
Don't get me wrong. I think he should be locked in a small shed forever and thrown a crust of stale bread every now and then for the rest of his natural life. It is merely that his situation is curious, to me. In the light of his mother and brother receiving bail almost immediately, and yes, they blabbed on Rick and Trent, sure, but even so. .. it is curious.