If Davis lied -- and Workman did not fire the fatal shot -- then who did?
"There were only two weapons fired that night," says former Workman prosecutor Don Strother. "The weapons fired that night were Philip Workman's gun and Lt. Oliver's gun. And I don't believe Lt. Oliver committed suicide."
But consider the following:
Police reports filed immediately after the shooting refers to an "exchange of gunfire" between Workman and police officers.
Stoddard says he never pulled his gun during the encounter with Workman. But witness Garvin Null says in a sworn affidavit: "Stoddard, whose pistol was out of his holster, attempted to give me that pistol so I could chase the suspect."
An article in the Memphis Commercial-Appeal two days into the investigation also reports that police say Parker "exchanged shots" with Workman.
One witness also says in a sworn affidavit that he saw Parker fire a shotgun at Workman. That witness, Steve Craig, was a friend of Stoddard.
Even though Parker never admitted to carrying a shotgun, fellow police officer O.W. Stewart told police investigators that he saw Parker with a shotgun.
Hospital records also show Workman was treated for "shotgun pellets to buttocks." But Workman, who says he was on drugs that night, testified at his trial that he did not recall being shot. And the attending physician says he doesn't recall seeing any gunshot wounds either.
In addition, one of the defense experts, Dr. Cyril Wecht, says Oliver's wounds "would not be consistent with a shotgun." He added that the wounds are "much more consistent" with the type of .38 caliber handgun ammunition that the police carried in their weapons.
At Workman's clemency hearing, former Memphis police Lt. Clyde Keenan -- who headed the department's shooting investigation team -- testified neither Stoddard's nor Parker's gun had been fired. He noted that an examination can determine if a gun has been fired "if you see this weapon within a couple of hours after it's been fired."
Police reports show Stoddard's gun wasn't inspected until approximately 2 a.m. -- almost four hours after the incident.
Still, no witness reported seeing any officer firing a handgun, except for Oliver himself.
But Steve Craig -- the witness who says he saw Parker shooting -- says in a sworn affidavit that police told him "there was no need to talk about this ... unless it was with someone from the department."
The U.S. 6th Circuit Court of Appeals found that allegation "troubling," but decided it wasn't relevant because Craig says he saw Parker shoot only after Lt. Oliver had been shot.
Defense lawyers, however, question why the officers wouldn't admit to firing shots at a man who the government claims had killed a cop and was trying to get away.
That leads them to question whether Oliver may have been hit by friendly fire.
"It's the middle of a crime scene," Jefferson Dorsey says. "Weapons are being fired. I'm not sure the officers on the scene knew exactly what was going on - to be charitable to them. Maybe they believed they didn't fire."
Asked if it mattered who fired the fatal shot - if Workman was responsible for the situation that led to Oliver's death -- the former prosecutor Don Strother says, "That would be for the jury to decide."
Defense lawyers argue the jurors who sentenced Workman to death never heard evidence that someone else may have fired the fatal shot -- and they certainly never knew that the only witness who testified that he saw Workman shoot the officer may have been coerced by police into giving false testimony.
(In fact, his court-appointed lawyers put on no testimony whatsoever in the sentencing phase of the trial about why their client should not be executed.)
But Officer Stoddard insists, even if the testimony of a government witness was completely fabricated, Workman should be put to death anyway.
"You'll never make me believe he didn't do it," he says.
Jefferson Dorsey counters, "Without Harold Davis' testimony, it was not a capital crime. That is the only direct evidence that makes Philip Workman eligible for the death penalty."
As for Workman, the condemned man says:
"I've always held and still do hold myself responsible for creating the tragic event. If I am going to be executed just for that aspect, I understand it -- although that is certainly not the law."