The fight between George Zimmerman and Trayvon Martin began with two people huffing and puffing in the dark, and then a brief exchange of bitter words.

It wasn’t long before the two were wrestling on the ground, and one of them let out such gut-wrenching howls that several people in the neighborhood thought they might have come from dogs. Witnesses said the tussle grew louder as it made its way up a dark pathway, past several patios, from the concrete back on to grass.

From there, witness accounts diverge.

“The one guy was throwing blows MMA style,” a witness dubbed W6 told Sanford Police, later explaining his reference to mixed martial arts. “The one getting beat up, I’m guessing he was yelling out help, because he didn’t want it to come to that point, and then it came to that point where he was on the concrete. I don’t know if you ever got hit on concrete, it hurts.”

His recorded interview with Sanford Police was just two minutes long.

But like several of the nearly two dozen witnesses interviewed by four different law enforcement agencies, Witness Six was hampered by darkness and, the evidence suggests, influenced by news. A review of the testimony of witnesses to the Feb. 26 killing shows several of them modified their accounts or grew skeptical of their own recall after weeks of heavy news coverage that included marches across the nation demanding Zimmerman’s arrest. Several said they reshaped their stories because of what they learned on TV.

In addition, some people heard a second shot that was never fired and saw shirts nobody wore. Together, the testimony they offer is contradictory, possibly of little evidentiary value, and underscores the unreliability of eyewitness testimony in criminal cases.

“Memory does not function like a videotape that records everything and can be replayed at will,” said Karen Newirth, an eyewitness identification litigation fellow at the Innocence Project, a national organization that works to exonerate innocent people. “People remember pieces of events, and then fill in the blanks with what makes sense.”

Based on the descriptions he offered, witness No. 6 — most of the witnesses in the case are identified only by number on prosecution records made public last week — saw Trayvon Martin on top of Zimmerman, punching him. But when he was interviewed three weeks later by the Florida Department of Law Enforcement and a local prosecutor, No. 6 said maybe the man on top wasn’t throwing any punches, and perhaps was just pinning the guy down until the police came. Maybe it wasn’t the guy on the bottom calling for help after all.

“That’s just an assumption,” he said. “I can’t tell who was yelling.”

One witness, No. 2, told Sanford Police she saw two people running, and later, when prompted, she clarified that the space between them was about 10 feet. She saw a “fistfight” – “fists” – she stressed. A week later, she told the same detective that she “more heard it than saw it,” and did not have her contact lenses on.

“It was a glance, running,” she told Sanford Det. Chris Serino. “I kinda more heard it than saw it. I heard it.”

When she met with FDLE investigators, she said she “saw something out there,” perhaps just one person whose feet she heard running.