LOS ANGELES — Did Lana Clarkson die immediately after a gun discharged in her mouth, or did she survive long enough to take a few blood-choked breaths?

The length of time between gunshot and death has become a central issue in Phil Spector's murder trial as the case limps to a conclusion.

The music legend's defense has suggested Clarkson may have aspirated blood, offering a benign explanation for some of the prosecution's most damning evidence — tiny red drops on Spector's jacket. (VIDEO)

For more than three hours Thursday, a defense expert insisted that blood in Clarkson's lungs is proof she breathed in after a bullet from a .38 Special struck her spinal cord Feb. 3, 2003.

Dr. Werner Spitz, a Michigan forensic pathologist who testified previously in the case, returned to the stand to describe a mixture of air and blood in the air sacs of Clarkson's lungs, which he said could only be the result of a drawn breath.

Story continues

"There was inhalation," he told jurors.

He rejected a prosecution expert's testimony earlier this week that gravity forced the blood into Clarkson's lungs. Clarkson, 40, died sitting upright in a chair in Spector's foyer, and her body remained in that position for 12 hours.

Prosecutors claim Clarkson was immediately incapacitated by the injury. They have said the 18 spots on Spector's white dinner jacket are proof he was standing within 3 feet of Clarkson when the gun went off.

Under direct examination, Spitz said that he had read a textbook recommended by the prosecution expert to prepare for his testimony and that its chapter on respiration convinced him that she could have inhaled even if her spinal cord was severed completely.

"I didn't even know that until I read this. There will be an intake of air and expulsion of air for a period of time," Spitz said.

Later, under cross-examination, a prosecutor charged that the pathologist had misread the textbook and that, in fact, there was no way for nerve impulses to activate the breathing muscles if the spinal cord was severed.

Spitz, whose career spans 54 years, acknowledged that it had been five decades since he studied physiology, but refused to concede the point.

He said that perhaps the bullet had only partially torn the spinal cord, allowing some nerve signals to get through, but that in the end, the blood in the lungs left no doubt that breathing took place.

Spitz was the third pathologist to testify at length about the possibility of dying breaths, and jurors appeared to struggle to pay attention to his testimony. Only one of the 17 panelists took notes consistently during his time on the witness stand.

Jurors also heard from a psychologist contacted by Clarkson a month or two before her death. Dr. Mary Goldenson testified that the actress phoned her in late 2002 or early 2003.

"She wanted to come in and discuss issues with me," Goldenson recalled.

She said Clarkson was concerned about her fees. "She told me she had no insurance and that she was handling the matter and would get back to me," Goldenson said.

Clarkson never called back.

The defense is to call the final witnesses in the trial Monday. Scheduled to testify are two of Clarkson's friends, Jennifer Hayes-Riedl and Punkin Irene Elizabeth Laughlin. Both women previously described Clarkson as depressed at the time of her death.

Spector, 67, faces 15 years to life in prison if convicted of murder. His defense claims the actress shot herself.