After lunch recess, de la Rionda questioned Singleton about Zimmerman's injuries and showed pictures of the injuries taken the night of the shooting at Sanford Police Department.

A video of Zimmerman giving samples to police in the interview room was then shown to jurors. Singleton then told a story about Zimmerman asking her about a cross she was wearing and if she was Catholic.

O'Mara cross-examined Singleton, asking how Zimmerman reacted to hearing Martin had died. Singleton said Zimmerman asked, "he's dead?" then dropped his head and shook it.

Singleton also said Zimmerman never refused to speak to police. The state objected to the defense citing evidence that Zimmerman said he was the one screaming on the call but Nelson overruled the objection.

O'Mara described Singleton's questioning of Zimmerman as a "virgin interview" where neither party knew evidence or witnesses yet. He also discussed Zimmerman's reaction to finding out Martin died and Singleton's religion conversation with Zimmerman.

O'Mara also asked Singleton about Zimmerman's statements and any inconsistencies.

Singleton said she saw "no inconsistencies" in statements, adding "Most people don't tell you the same story the exact same way two times." She also said she saw no "significant discrepancies in Zimmerman's interviews with her compared to the statements he gave Serino.

Singleton also said she suspected Zimmerman didn't get out of his car to look for street signs, rather he wanted to get out of the vehicle. She said she would have thought Zimmerman knew the street signs because he was part of the Neighborhood Watch program.

O'Mara then asked if Singleton found it unusual that Zimmerman called Martin a "suspect" in statements. She also said she didn't think it was significant that Zimmerman said Martin came from the bushes and then said he didn't know from where Martin came from. She was shown pictures of the bushes.

During redirect, de la Rionda got Singelton to agree what is significant or not is up to the jury.

De la Rionda asked if Singleton knew what was in Zimmerman's heart or mind when he followed Martin, calling him an "unarmed 17-year-old boy." Singleton said she only knew what Zimmerman told her.

O'Mara then asked if Zimmerman seemed spiteful or angry, to which Singleton said he didn't.

Entering the second week of testimony Monday, prosecutors first called Federal Bureau of Investigation forensic examiner Hirotaka Nakasone, a senior audio electronic engineer. Nakasone previously stated he couldn't identify if it was Martin or Zimmerman screaming in background the 911 call.

Prosecutor Richard Mantei questioned Nakasone about his previous testimony on the reliability of speaker recognition technologies. Nakasone said he was asked to analyze eight recordings for the Zimmerman case, including 911 calls made by neighbors who heard the shooting.

Nakasone said guessing age from voice recording can be "a little complicated" and can often result in mistakes. He said people can identify familiar voices even after a few words. If that were to be true, Martin's mom, Sybrina Fulton, may have been able to identify her son's voice and Zimmerman's family may have been able to identify his voice.

"For this particular case, best approach would be familiar voice recognition by an individual who has heard him in his whole life speaking, uttering in a variety of conditions including screaming, yelling, under similar setups," Nakasone said.

Nakasone said where it gets "tricky" is with unfamiliar voices. Nakasone said comparing two unfamiliar voices is very difficult. He said it's "better" to identify a voice by human recognition than using technology. Juror 5, E6,  nodded gently, as if agreeing.

During cross-examination, defense attorney Don West asked about the reliability of voice analysis software. Nakasone said most scientists agree voice analysis of screams are unreliable. Nakasone also added there could be "bias" in voice recognition.

West then asked Nakasone about his opinion on law enforcement practices. The state objected and Judge Debra S. Nelson ruled she wouldn't allow the question.

West then attempted to have Nakasone say "listener bias" was an issue when the 911 call was played for Martin's parents. West asked if the call was played for more than one person, if there was an increased risk of infecting the reliability of identification, to which Nakasone responded it could if bias was built in.

"Did you consider screams to be of someone in a life-threatening situation?" West asked.

"Yes ... extreme emotional state," Nakasone said, adding that it's not possible to determine age by listening to screams and undercutting the state's previous witness who testified that they thought it was screams of a younger person.

During redirect, Mantei asked Nakasone if bias was only an issue with unfamiliar voices, but Nakasone said a safeguard against bias also is needed with familiar voices. He said he would recommend listening to the audio clip separately and not in groups.

Nakasone previously testified as a witness for the defense in a Frye hearing, which resulted in state audio experts not being able to testify in Zimmerman's trial.

More than 20 witnesses testified during the first week of a trial that has opened up national debates about race, equal justice, self-defense and gun control.