Testifying Friday at the murder trial of Joseph Bearden, who is accused of killing a 25-year-old gay man, Associate Medical Examiner Vera Volnikh said a slash to the throat 3.5 inches deep killed Ryan Keith Skipper, who quickly bled to death.

Co-defendant William David Brown Jr., 22, is also accused of the murder, and will be tried separately in Polk County, Florida. Bearden, 23, is the first to stand trial.

“If the bleeding is not [stopped] within several minutes, the brain will die,” Volnikh said.

It also appeared as if Skipper attempted to fight off his attackers. Cuts found on the victim's hands, wrists and arms indicate he tried to block the knife, said Volnikh, who performed Skipper's autopsy.

Some cuts were deeper than others, leaving the possibility that Skipper's 163-pound body blunted the blades of two knives.

“It could have been two different knives,” she said.

The trial opened with the testimony of the woman who made the ghastly discovery of Skipper's bloody body stabbed to death sitting on the side of a dirt road that leads to the small town of Wahneta in the early hours of March 14, 2007.

Charlotte Upchurch testified that she never actually saw Skipper's face, whose body was lying face down in the road.

“There was a man's body lying in the road ... I called out to him, and there was no answer and no movement,” she said.

And on Thursday, jurors heard from the defendant himself. In an audiotaped interview between Bearden and police investigators made shortly after the murder, Bearden confessed being with Skipper on the night of the murder, but insisted he had nothing to do with his death.

Bearden has remained in custody over the past two years.

On Friday, CNN In Session interviewed the defendant's adoptive mother, Carolyn Bearden. She shared the significance of a tear drop tattoo her son got while in custody. The tattoo, located under his right eye, symbolizes being incarcerated during the death of a loved one. Bearden's cousin Ruby died of an asthma attack while he was in jail. He got another tattoo, a dagger painted around his left eye, also while in custody. And she also told the reporter that her son was beaten up “real bad” when he first entered jail.

Bearden's jailhouse attack and tattoos might prove significant when he takes the stand – possibly as early as next week.

Police investigators say a witness claims that Skipper was killed because he was making sexual advances towards one of the men. Investigators first said Skipper picked up Bearden while driving looking for sex, and that the two smoked marijuana at Skipper's house and conspired to commit check fraud using a notebook computer. Claims friends, family and gay rights groups have decried as character assassinations.

Skipper's parents turned to gay activism after the death of their son. Lynn Mulder, Skipper's stepfather, heads the Polk County chapter of PFLAG.

Bearden's trial is expected to last three-to-four weeks. If convicted, he faces the death penalty.