Testimony began today in the murder trial of a 28-year-old San Francisco woman accused of fatally stabbing the 18-year-old father of her child in December 2008, an attack that her attorney says was self-defense.

DeEbony Smith was arrested after turning herself in to police on Jan. 2, three days after her estranged boyfriend Lazarus Pickett was found stabbed outside a home in the 600 block of Larch Way, located in a public housing complex in the city’s Western Addition neighborhood. Pickett died at the hospital.

Smith and Pickett, the father of her then 2-month-old child, had reportedly argued about a baby seat and a diaper bag that she wanted returned to her.

During a confrontation inside Smith’s parked car that morning, Smith allegedly stabbed Lazarus in the heart.

Assistant Medical Examiner Dr. Judy Melinek testified today that the knife penetrated four to five inches into his chest.

There is little dispute that Smith stabbed Pickett, but Smith’s attorney Teresa Caffese has argued that she was defending herself against an assault by Pickett in which she suffered a fractured orbital bone around her eye.

The couple had a history of domestic violence, Caffese said, and Pickett had reportedly violated a stay-away order.

Prosecutor George Butterworth has argued that Smith indicated she was conscious of her own guilt when she told a police officer by phone following the stabbing that “I know I’m going to prison for this.”

The phone conversation took place before Pickett had died and before Smith agreed to turn herself in.

Witnesses who gathered at the scene of the stabbing also reportedly told police Smith was responsible, according to Butterworth.

Melinek testified today that a CT scan taken in early April showed Smith had indeed suffered a “months-old” orbital fracture, though she could not say who caused it.

Photos taken in the days following the stabbing also showed Smith had a swollen lip, Melinek said.

Caffese argues that Pickett caused the injuries. She said she plans to call Smith to testify during the trial.

“We knew an altercation occurred in the car,” Butterworth said after today’s court session. “The issue is the sequence.”

The prosecution case is expected to continue at least through the end of this week.

Pickett’s funeral was also marred by violence, when shots were fired at a procession of mourners as they were leaving. Two men were later arrested in connection with the incident.

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