Last month, Shanduke McPhatter sat in a Brooklyn courtroom, staring at the prospect of a murder conviction.

Four eyewitnesses had identified McPhatter, a 26-year-old from Park Slope, as the shooter in a 2002 slaying near the Gowanus Houses. Another witness reported seeing McPhatter flee with a gun.

While his mother prayed for him, even McPhatter’s defense lawyer came to believe his client would be found guilty and spend 25 years to life in prison. In an extraordinary turn of events, murder charges have been dismissed against McPhatter after an inmate and old friend made an apparent confession to the killing and turned the prosecutors’ case upside-down.

Last week, prosecutors moved to dismiss the case, and McPhatter was released from jail in time to spend Thanksgiving with his two twin sons and family.

“I still haven’t really understood it yet,” McPhatter, a former model, said yesterday from his mother’s home. “It’s a weight lifted off my shoulders.”

McPhatter’s defense lawyer, David Walensky, said the case illustrates the potential perils of eyewitness testimony.

“Eyewitnesses are notoriously bad,” Mr. Walensky said. “It scares the hell out of you – it shows how easily innocent people can go to jail, and it happens all the time.”

Prosecutors aren’t saying that McPhatter is innocent, but they dropped the case because of new doubts raised last month by Mr. Walensky.

On a long shot, Mr. Walensky had decided to visit the inmate, Jarel Moore, in prison on a Saturday afternoon during jury selection for his client’s trial.

McPhatter, who knew Moore from his neighborhood, had said that Moore would provide helpful information about the case. Mr. Walensky said he never expected Moore to confess.

“We started to talk. He said, ‘Your guy didn’t do this,'” Mr. Walensky said. As the lawyer brought Moore chicken wings and candy bars, the inmate confessed to shooting 18-year-old Abayomi Abidekun during an alleged drug turf dispute, Mr. Walensky said.

Mr. Walensky said Moore provided him with highly detailed information about the shooting, including a diagram of the murder scene and a letter to McPhatter that, according to the lawyer, read: “I am taking the rap, dawg, these witnesses are lying on you … I know that you’re innocent.”

The defense lawyer told Assistant District Attorney Stephen Murphy, who went to Moore’s prison to investigate. Moore said McPhatter was innocent, but he denied killing Abidekun.

Still, Moore, who was serving a four-year sentence and potentially stood to lose by injecting himself into the murder case, had raised troubling questions. Prosecutors, who knew and trusted Mr. Walensky, gave McPhatter a lie-detector test. He passed, and they moved for dismissal. Prosecutors say there is a “possibility” that McPhatter is wrongly accused, but they are not convinced.

“It’s enough to make you pause,” one law enforcement official said, adding that, for that reason, “you shouldn’t be charging someone with murder.”

Detectives had focused on McPhatter after receiving an anonymous tip, his lawyer said. McPhatter, whose record includes a felony robbery and misdemeanor drug convictions, refused to speak to detectives. He said he didn’t trust the police and planned to keep silent until his trial. McPhatter also said he didn’t want to “snitch.”

It is unclear if prosecutors now will try to build a case against Moore, with so many witnesses ready to blame McPhatter. McPhatter says he does not know who shot Abidekun, but he accused police of pressuring witnesses into implicating him.

“Some people are eyewitnesses, and some people are just liars,” he said. “It’s a dog-eat-dog world.”