Few people outside the criminal justice system understand just how much power a prosecutor has to charge someone. In felony cases they must present the case to a grand jury, but the burden to obtain an indictment is low; they must only present enough evidence to establish a possibility the defendant may be guilty. Grand jurors don't decide guilt or innocence, but only whether the case should go to trial. The problem is the presentation of evidence is one sided; grand jurors only hear from the prosecutor, and you expect them to present the best evidence they have.
Once an indictment is returned a defendant may have to wait for a trial to prove his or her innocence. That may take a substantial amount of time - in some cases years. While the defense lawyer can present evidence to the prosecutor and try to convince them to dismiss the charges they don't have to listen. There may not be enough evidence to obtain a conviction, but there is nothing you can do about it. You just have to wait for trial - and you may be waiting in jail.
Occasionally people will ask whether they can have a hearing to force a prosecutor to present their evidence and show they have enough to proceed forward. Unfortunately there is no procedure for doing that, at least in Texas. The prosecutor is not accountable to anyone; they alone get to decide when a case is dismissed.
This isn't a big deal in most cases, because the State usually has more than enough evidence to obtain a conviction. It can be extremely frustrating though in those cases where you know the State doesn't have a case.
So what happens in cases like this? Sometimes the prosecutor will go right up to the date of trial and dismiss the charges. The more common situation is for the prosecutor offer a plea to a lesser charge. That may be extremely attractive to defendant who has been in jail for awhile, and is guaranteed to get out. If the case does go to trial a judge can grant a motion for directed verdict when the State rests it's case. That means the judge tell the jury to find the defendant not guilty. The final alternative is to submit the case to the jury, and hope they agree with your assessment of the evidence.
Thankfully not all prosecutors use the system like this. There are some who don't hesitate to dismiss a case when they believe the evidence is not there - even when the believe the defendant is guilty. Those prosecutors recognize that their job is to make those decisions. and not leave everything to a jury.
The stress on a defendant and their family is tremendous. Anytime you leave your fate in the hands of a jury you have reason to be concerned. This is where you have to trust your lawyer; to not only guide you through the process, but provide the assurance that everyone possible is being done to prepare your case.