Frey's attorney, Gloria Allred (search), briefed reporters after the ninth day of testimony in Modesto, Calif., saying that her client would not appear in the hearing -- a decision made by the district attorney.
Allred said she didn't know why the decision was made not to have Frey take the stand, but speculated that it was a decision to ensure that Frey would not be "made a victim" by the defense.
There's been a great deal of speculation about Frey's testimony, in light of her cooperation with Modesto authorities during the search for Laci Peterson (search). In the preliminary hearing, it's been revealed that Frey began helping police once she found out that Peterson was married. That assistance included the taping of conversations.
Peterson allegedly told Frey, a massage therapist from Fresno, that he was a widower two weeks before his wife Laci disappeared, according to police testimony.
At the hearing to determine if the murder case against Peterson will go to trial, his defense attorney suggested the detective investigating Laci's murder took it personally and wrongly ruled out other viable suspects.
Defense attorney Kirk McAllister suggested that Modesto Police Det. Al Brocchini (search) had told friends of the couple that he was going to "take Scott Peterson down."
Brocchini denied making the statement, but acknowledged he tried "planting the seeds of suspicion" with a friend of Scott Peterson with a different goal in mind.
"My intent was to catch, to get, whoever got Laci. That was my intent and still is," he said, adding that he followed all leads when questioning Scott Peterson's friends.
The remains of the 27-year-old substitute teacher and her unborn son washed ashore in San Francisco Bay in April only a few miles from where her husband said he was fishing Christmas Eve, when she vanished. Scott Peterson, 31, later was arrested and charged with murder.
McAllister also suggested that Brocchini tried to get Scott Peterson fired from his fertilizer sales job, which the detective denied.
Brocchini said he worked with the company to review Scott Peterson's expenditures. Some spending records had been subpoenaed.
Fox News' legal analyst Stan Goldman, Fox News' Rita Cosby and The Associated Press contributed to this report.