Judge Alfred Delucchi looked to defense lawyer Mark Geragos to begin questioning Frey. There was silence.
"No questions, your honor," Geragos said. The courtroom was abuzz with whispers. The judge looked bewildered, his mouth agape. Prosecutors seemed stunned.
"Just kidding," Geragos said with a grin, prompting muffled chuckles among a few jurors and members of the audience. The attorney then launched into his questions for just 10 minutes before the trial broke for lunch.
This is Frey's third week in the courtroom but the first time the prosecution's star witness has had to face hostile questioning by Geragos, who can be ruthless with witnesses, reports CBS News Correspondent John Blackstone.
Geragos asked Frey about the first time she spoke with Peterson and began asking Frey about the phone calls with Peterson that Frey taped at the request of detectives investigating what turned out to be the murders Peterson is now charged with: that of his wife, Laci, and their unborn child.
"If this were a prize fight and it was in the fifth round, it would be five for Amber and zero for Geragos," Frey's attorney, Gloria Allred said on CBS News' Early Show. "He never touched her. He never even came close to making it interesting. He didn't have facts to impeach her credibility and that was his problem. He would have been better off if he said, 'no questions,' and he meant it."
Prosecutors allege Peterson killed his wife, Laci, in their Modesto home on or around Dec. 24, 2002, then dumped her weighted body from a small boat into San Francisco Bay. Defense attorneys claim Peterson was framed by the real killer, who they have not named.
Last week, jurors heard 40 wiretapped calls between Frey and Peterson during which he was apologetic for lying to her about being married but evasive in his answers about his wife's disappearance and the couple's relationship. He continued to romance Frey even as police searched for his missing wife.
During cross-examination Monday, defense attorney Mark Geragos prodded Frey about the taped calls, implying she did not fully cooperate with police.
According to police reports, authorities were suspicious that Frey may not have been taping all of her calls with Peterson or may have neglected to turn over some tapes, Geragos noted.
Frey maintained she cooperated fully.
"I recorded all conversations," she said.
"Did you ever not turn over tapes?" Geragos asked.
"I turned over every tape that I recorded," Frey replied.
"Did you ever make or receive calls from Scott Peterson that you didn't immediately tell detectives about?" Geragos prodded.
"No," Frey said.
"At any point did you hide any information... from the Modesto Police Department?" Geragos again asked.
"No," Frey said, answering questions in an even-toned voice directly to Geragos, never looking at Peterson or the jury.
It appeared Geragos was preparing to try to prove that Frey spoke to Peterson without alerting authorities. She acknowledged she was unaware that police had also wiretapped Peterson's telephones.
Geragos also tried to downplay the prosecution theory that Peterson was obsessed with Frey, and that the affair was his motive for murder, portraying the relationship as one-night stands where Peterson could simply get sex.
Geragos noted that on Dec. 26, 2002, Frey called Peterson 14 times. She said she wanted to thank him for a Christmas gift.
Geragos later portrayed Frey as a calculating seductress who would try anything to trap Peterson into admitting he was involved in Laci's disappearance.
Frey testified she told police she had sex with Peterson at least three times.
"At that point you tell them you could basically use the ruse that you were pregnant and they could use that ... and see if that would elicit some information?" Geragos asked.
"That was the concept," Frey said. "At that point, I was willing or open to anything... in assisting the police if that would help in any way."
Peterson never admitted involvement in the crime in the wiretaps that were played for jurors.
"The idea was to try to get him to admit something, to admit some involvement, that he had something to do with Laci's disappearance?" Geragos asked.
"I questioned him many times in different ways, yes," Frey replied.
Frey is due back on the stand Tuesday.
Earlier Monday, a wireless telephone expert testified about Peterson's cell phone records in the days after his pregnant wife, Laci, vanished. Authorities used cell phone towers to track Peterson's calls and movements on Dec. 24, 2002, the day Peterson reported his wife missing.
Mary Anderson, of West Palm Beach, Fla., works for AT&T Wireless as the director of national subpoena and court order compliance.
Prosecutors are working to establish a timeline that they say places Peterson near his Modesto home within 10 minutes of when a neighbor said she found the Peterson's dog loose in the neighborhood, indicating Laci Peterson had already disappeared.
Anderson said cell phone records indicate Peterson made a call to his voicemail at 10:08 a.m. on Dec. 24. That call bounced off a cell tower near the Modesto area, according to the records.
But on cross-examination, Anderson acknowledged the records "are not 100 percent accurate," meaning Peterson may have been nowhere near his Modesto home when the call was made.
Geragos pointed out that other calls placed by Peterson while he was standing in his front yard indicate the calls bounced off of several different towers.
Anderson testified that cell phone calls to voicemail cannot always be accurately tracked to specific towers.
"There appear to be some anomalies there," Anderson said.