So far, the courts have refused to consider the ballistics issues, partly because of eyewitness testimony.
In fact, the prosecution presented only one witness who testified he actually saw Workman shoot Lt. Oliver.
That witness, Memphis native Harold Davis, came forward the day after the shooting. Davis, a drifter with a history of drug abuse, testified he was parked outside the Wendy's when he saw the altercation, got down on the ground and witnessed the shooting. Afterwards, Davis says he ran off, leaving his automobile in the Wendy's parking lot.
Speaking to the jury that they would ask to deliver a death sentence, prosecutors characterized Davis' testimony like this:
"Harold Davis ... virtually saw the whole thing. Was it a thing where they were wrestling over this pistol? No. Was it a thing where the lieutenant was trying to get the pistol away and there's an accidental discharge? No....
"He (Workman) cooly and deliberately pulled this trigger and sent the bullet down this barrel and into the body" of Lt. Oliver.
But our NewsChannel 5 investigation discovered serious problems with Davis' testimony.
In fact, Davis' car isn't visible in photos taken of the crime scene, and it doesn't show up in police diagrams. And no one saw him there -- not even the police officers who had been warned to be on the lookout for an African-American man who had been robbing area Wendy's.
"I didn't see him," Stoddard admits.
And a source deeply involved in the police investigation tells NewsChannel 5, "I never believed that Harold Davis was there."
Witness says Davis elsewhere
A close Davis friend, Vivian Porter, tells NewsChannel 5 investigative reporter Phil Williams she's certain that Davis lied.
Porter knows, she says, because she was with him the night of the shooting. Porter, who now runs a Christian drug rehabilitation center, says she and Davis were out buying drugs when they were stopped by a police officer.
As he walked up to their vehicle, Porter says the cop got an emergency call. He "stopped before he got to us and immediately got back into his car and sped off. We sat there, panting, because we were both preachers' kids and we were talking about how good God is -- a narrow escape once again."
Later, they drove by the Wendy's crime scene and realized the officer was responding to the shooting, Porter says. "It was kind of taped off, you know. So that told me that whatever had transpired on the parking lot had already happened."
So why would Davis lie about having seen the shooting?
Davis' own sister, Jacqueline Davis Moden, tells NewsChannel 5 that Davis was a drug addict who made money by "professional witnessing."
She says he would scan news reports looking for details about crimes. "Then claiming to have personally witnessed it" so he could collect the reward money.
After he went to police in the Workman case, the unemployed Davis suddenly had money, she adds. "A large sum of money, I don't mean 5 or 10 dollars. But he had a substantial amount of money that was questionable to how he would have come about it."
There is no proof Davis received a reward. But Vivian Porter adds: "When he called to say that he witnessed it, it had to have been about money. Because when you are in your addiction, sometimes you'll do anything to get your drugs."
Davis recants testimony
And, now, Harold Davis himself says he lied.
In October 1999, defense lawyers tracked Davis to a Phoenix motel. In an interview the lawyers videotaped, Davis told them he was not in the Wendy's parking lot on the night of the shooting.
"Did you see Philip Workman shoot the police officer?" one of the lawyers asks Davis in the video.
He replies: "No, I didn't."
At the time, Davis still insisted he was near the Wendy's where he could see some of the struggle in his rearview mirror. But, he adds, "I never said that I saw the guy shoot the policeman. I never said that."
Davis adds that he did not want to testify against Workman, but police threatened him. "I could get arrested as a hostile witness, and they could stick me in jail until the trial was over with."
In November, Davis landed in jail on a minor charge. He began calling NewsChannel 5 investigative reporter Phil Williams repeatedly, hinting there was more to his story. At one point, he wanted to know if he could be prosecuted for perjury if he admitted it was all a lie.
"I don't want it to go on my testimony because I was not really sober that night and everything else," Davis tells NewsChannel 5.
After being released from jail, Davis agreed to one last videotaped interview with defense lawyers. On that tape, the former prosecution witness breaks down into tears over the prospect of Workman being put to death.
"I don't want to see him die for something he didn't do," Davis cries. "I was hoping it wouldn't come to what it came to."
Davis claims he was in the neighborhood when the shooting occurred, but he didn't see it. Still, for reasons he doesn't explain, Davis says he went to police the next day.
"They basically told me what happened. And would you be willing to say this happened. I said, I didn't see all that. They said, well this is what you are going to say."
That day, Davis signed a statement describing the shooting in great detail.
Then, when it came time for Philip Workman's trial, Davis says he again tried to back out.
"I kept telling the prosecutor I really don't feel good about this," Davis adds. "Late one night, a big white guy came and knocked on my door. He said he had a message for me and that, if I changed my testimony in any kind of way, people I love and care about could disappear just like I could."
Officer Stoddard admits that Davis' claims trouble him somewhat.
The retired officer says he pulled out a stack of old newspaper clippings after he dreamed he saw Davis' car in a crime scene photo.
"But it's not there in the picture?" Phil Williams asks Stoddard.
"No," he replies, "and I don't recall seeing it. I just dreamed that I did."
Prosecution says Davis now liar
Still, the former prosecutor, Don Strother, denies anyone pressured Davis to say anything. In fact, he says Davis must be lying now.
"I believe now, and I believed then, that Mr. Davis told the truth," Strother says. "I believe he testified under oath truthfully in court."
Defense lawyers, however, argue Davis' emotions are real -- and the evidence at the crime scene matches his current story that he wasn't even there.
"No man should be put to death based on perjured testimony," Workman lawyer Jefferson Dorsey says. "We now know that Harold Davis' testimony was perjured."
Dorsey says his claims also raise a disturbing question about the police investigation.
"Why go to all the trouble to threaten, to coerce somebody into committing perjury in a capital trial? The only solution in my mind is there is something they feel the need to hide."