I believe they are both involved.
http://latimesblogs.latimes.com/spector/
Gregory Diamond, former clerk to defense attorney Robert Shapiro, just took the stand and said he was at Phil Spector’s house and saw another lawyer then working with Shapiro pick up a small, white item and hand it to forensics expert Michael Baden, also a member of the defense team
Ah, so they've brought out the big guns (Dr. Baden) for the defense. Look out. Specter will walk.