Tirrell Edwards is said to have killed 46-year-old Amanda Williams during an argument in their home in October.
While the prosecution is asserting murder, Edwards' defense team says that Williams attacked him with a knife, and that Edwards shot her six times in self-defense.
First to the stand on Wednesday was Cuyahoga County Deputy Medical Examiner Dr. Elizabeth Mooney.
She told the courtroom that the cause of Amanda Williams' death was gunshot wounds and the manner of her death was homicide.
She found eight gunshot wounds on Williams' body.
The prosecution asked her if the six gunshots fired by Edwards could create the eight gunshot wounds, and she said yes, because one bullet could create multiple wounds.
Dr. Mooney said one of the bullets completely separated two of the vertebrae in Williams' upper spinal column, which certainly paralyzed Williams' upper and lower body, and possibly could have been fatal. But she then explained that there was no way that Williams could have survived the bullet that went through her heart.
Here is her response when the prosecutor asked her if the bullet that went through her heart was fatal by itself.
"Yes," she said. "Injuring the heart and aorta, those will cause bleeding very, very quickly. Not much chance to repair that."
The courtroom became very emotional when the prosecution next showed photos of Williams' dead body at the medical examiner's office. Her family could be seen crying, and even a juror wiping tears from her eyes.
As for Edwards, he put his head down for this entire part and didn't raise his head again until they were done showing the pictures.
The prosecution later brought Curtiss Jones to the stand. He's the Supervisor of the Trace Evidence Unit at the Cuyahoga County Medical Examiner Office.
He determined that a gunshot hole in Williams' arm sleeve was shot from less than a foot away.
At one point, they asked him about cuts in the stomach area of the shirts Edwards was wearing the night of the killing. Jones said he could not conclude what caused the shirt cuts but did say they did not find any fibers from the shirts on the knife Amanda is accused of holding.
Edwards also had no physical injuries to his stomach.
When Lisa Moore, a DNA Analyst for the Cuyahoga County Regional Forensic Science Laboratory, was on the stand, both the prosecution and defense asked her about DNA on the handle of the knife.
"A likelihood ratio was calculated assuming item 35.1 contained DNA from four unknown contributors," she said of the knife handle. "A match was identified between item 35.1 and Amanda S. Williams."
A defense attorney asked her, "But in the end, you cannot say that Tirrell Edwards' DNA was on the knife, correct?"
"Correct," Moore then responded.
As for the knife blade, a DNA match was made for Williams but not for Edwards.
Testimony continues Thursday morning. The prosecution said first to the stand will be a lieutenant for the Warrensville Heights Police Department.