The gifts are beautiful, and very thoughtful!
I agree that it is best to refrain from any contact with the prosecutor (or judge, defense attorneys, investigators, or witnesses!) till the case is over. If we remember back to the CA case, there was a conflict of interest when the judge and a blogger had contact, and caused the judge to recuse himself. That is no small impact. Our goal should, imo, always be to not insert ourselves into the trial process, while showing support to the family of the victims.
One of the things we did at another site, after the case was over, was to have a "thank you" thread for the prosecutors. (And we received repeated confirmation that they had seen the messages!) Members could drop by and leave messages of support and encouragement, admiration, etc. We also sent a gift basket to the prosecutors, but again, after the case concluded. We included several of the prosecution witnesses, also, in our thank you thread. This is a very non-intrusive way, IMO, to express the thanks and appreciation of the "common citizens" following the trial. It is something we can consider, when the trial concludes.