Spector is accused shooting and killing Clarkson at his Los Angeles-area home in February 2003. Spector contends she shot herself.
Left undecided were motions from both sides concerning Clarkson's mental state prior to her death. The prosecution wants the information excluded while the defense wants it aired at trial.
Los Angeles County Superior Court Judge Larry Paul Fidler on Tuesday granted a prosecution motion to allow testimony from Devra Robitaille, a former employee and lover of Spector. Robitaille told investigators that Spector twice threatened to shoot her when she tried to leave his house. The judge earlier ruled four other women could testify that Spector threatened them with guns in the 1980s and 1990s.
Fidler ruled for the defense in its motion to bar the testimony of a security guard who said Spector ranted for two straight years about women at Christmas parties he attended.
Jury selection is expected to start next week.