Updated

The mother of the Charleston church massacre suspect collapsed when investigators came to her home the day after the shootings and started asking questions about her son, a sheriff's deputy testified Tuesday during the trial in South Carolina.

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Once the mother, Amelia "Amy" Roof, recovered, she showed the investigators her son's room, Richland County deputy Justin Britt told the jury. "We entered his bedroom and on the corner of his desk she grabs a camera, turns it on and shows the photos... pictures of Dylann with confederate flags at historical sites, holding a black gun. It was very evident why she thought this was important for us to see."

Amy Roof had suffered a heart attack in court during opening statements last week, according to defense attorneys. They did not give specifics on her condition.

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Roof faces 33 federal charges, including hate crimes and obstruction of the practice of religion, in connection with the shooting that killed nine people during a Bible study at Charleston's Emanuel AME Church in June 2015. Roof's attorneys have said repeatedly in both federal and state court that their 22-year-old client was willing to plead guilty if capital punishment were taken off the table, a request prosecutors have refused. Roof faces another death penalty trial next year in state court.

Also Tuesday, Roof's attorneys said they planned to call witnesses to testify in his defense after all.

Last week, attorney David Bruck said he didn't plan to put up much of a defense of  Roof, adding that the facts of the case were largely undisputed. But before jurors returned to court Tuesday, Bruck told U.S. District Judge Richard Gergel he planned to call "several" witnesses. He did not specify who.

Jurors have heard five days of testimony from prosecutors' witnesses, including law enforcement agents, forensic examiners and tech experts. An employee of Garmin, the company that made a GPS found in Roof's car, testified Tuesday that data from the device show he rode by the church in months leading up to the shootings. Timestamps from the device showed his car arrived at the church at around 7:45 p.m. the night of the shootings and left more than an hour later.

Another officer who helped search the home testified she recovered dozens of spent ammunition rounds, saying relatives told her Roof and others would practice shooting in a nearby wooded area. Kristen Polis also testified she photographed a white pillowcase cut into a triangle because "to me, it represents what could be a Ku Klux Klan hood."

Prosecutors have said they could wrap up their case as early as Wednesday. Late Monday, Gergel ruled Roof's attorneys couldn't present evidence related to their client's mental health during the guilt phase of his trial, saying it was more appropriate for the penalty phase.

If Roof is convicted, jurors would decide if he should be sentenced to life in prison or the death penalty. While he has a defense team at the moment, Roof has said he wants to be his own lawyer for the penalty phase.

Assistant U.S. Attorney Jay Richardson opened his case with Felicia Sanders, a survivor of the June 2015 shooting at Charleston's Emanuel AME Church. He has said he plans to close with testimony of another survivor, Polly Sheppard.

Fox News Multimedia Reporter Terace Garnier in Charleston and The Associated Press contributed to this report.