However, the court did allow one semi-exception to its rule: notice and demand regimes. Under these types of procedures, the prosecution gives notice of intent to use a certificate as proof and the defendant then has to demand the presence of the person who did the analysis or the defendant is deemed to have stipulated the content of the certificate as valid (waiving his right to confront). With this in mind, I went looking at the Virginia statutes governing this to see where we stand.
Under 19.2-187, as long as a certificate is filed with the clerk at least 7 days before trial it is admissible as evidence. Furthermore, upon filing the correct paperwork, the defense can require the court to send it a copy of the certificate at least 7 days prior to trial. 19.2-187.01 allows the certificate as proof of proper chain of custody. 19.2-187.02 allows blood reports taken at the hospital as evidence. 19.2-187.1 allows the defendant to demand that the person who did the analysis be present at trial (at prosecutor summons and cost) and gives the defense the right to "examine him in the same manner as if he had been called as an adverse witness."
One could wish that the statutory scheme was more tightly written, but it does appear that Virginia has a notice and demand structure in place. The notice is the required filing of the certificate of analysis no later than 7 days pretrial. Why else require a piece of the Commonwealth's evidence to be placed in the court file if not to give notice of the Commonwealth's intent to use it?
The demand part of the Virginia scheme is quite clear. The defense has an absolute right to demand the person who performed the analysis be present at trial under 19.2-187.1.
However, the language of 19.2-187.1 needs some serious reworking. It allows the defense "to call the person . . . as a witness therein, and examine him in the same manner as if he had been called as an adverse witness." While this does not impact notice and demand statutory scheme, it could give rise to burden-shifting arguments. The General Assembly needs to change that language to something like "to require the Commonwealth to call the person . . . as a witness therein" and it wouldn't hurt to drop the language after the comma (although it seems to just be a fancy way of saying "cross-examine"). As a practical matter, I've never seen a prosecutor not call the expert witness once the defendant has required the expert's presence and I think this may make any burden-shifting objection moot. Still, the statute needs fixing.
This statutory scheme was originally developed as a hearsay work around. It also presents the type of notice and demand regime required by the court to satisfy the Constitution's confrontation clause.