Some clients ask us why we can't get a copy of the testimony of police officers and witnesses who provided testimony to the grand jury. A grand jury is a body of citizens who serve on a rolling basis to decide if the prosecution as sufficient evidence to indict a defendant for an alleged crime. The standard of proof for an indictment is far less than the "beyond-a-reasonable-doubt" standard necessary for a conviction at trial. Nevertheless, the witnesses who testify at the grand jury are under oath - and thus defense lawyers would want to have the transcript of that testimony to see if that grand jury testimony is the same as the trial testimony. However, there are very limited circumstances where a defense lawyer can get the transcript of the grand jury testimony. The defense lawyer has to show "particularized need" (whatever that means) in order to get a special order to have the prosecutor present that transcript. As a practical matter, this almost never happens because most courts assume that the defendant can learn all he needs to know from the police reports and other evidence disclosed in the pretrial discovery process.
But we still try now and then - and have on some rare occassions gotten those transcripts in special cases.