One of my county attorneys has a juvenile investigation going on, in which a juvenile apparently sexually assaulted another child. A juvenile witness to this crime has not been forthcoming with police, apparently on the orders of his mother.

Can we (DA's Ofc) subpoena the mom to bring her minor son to the next G/J, so he might testify?

I have two concerns: 1) Is it proper for the G/J to be involved in an investigation which will not require an indictment to prosecute? 2) If the child refuses to testify, what sanction can you impose on him? Is he subject to contempt?

Any ideas how we can get the truth out of this kid?

Check out 53.035 of the Family Code.

I have used a GJ subpoena with juvenile witness and their parents before but have never had to go to the next level and file contempt. I think it is a viable option.

If you seek determinate sentencing, you need grand jury approval (unless the defendant waives it), and then you can get the kid in front of the grand jury. We used the grand jury all the time in Harris County for approval of our determinate sentencing juvenile cases. And if it's sexual assault, that's exactly the kind of case that's appropriate for determinate sentencing.