By Steve Tawa

PHILADELPHIA (CBS) — The Levittown, Pa. man accused of killing a doctor in her center city home in 2013 today completed his time on the witness stand.

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Assistant DA Jennifer Selber, chief of the DA’s homicide unit, spent 50 minutes cross-examining the defendant, 37-year-old Jason Smith.

Selber asked him how he knew the order of the gruesome events — that doctor Melissa Ketunuti was strangled, then tied, then burned — in the confession he gave detectives three days after her murder in her Naudain Street home, before the medical examiner ruled she was dead before her body was burned.

Smith responded no one knew that at the time.

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Smith also maintained that his confession came after detectives roughed him up in the police department’s homicide unit.

While the jury was out of the courtroom, defense lawyer Michael Farrell moved for a mistrial over the prosecution’s line of questioning that Smith might have considered a “mentally impaired” defense before moving to his not-guilty stance on all charges.

The judge denied the defense motion.

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