At the trial, the strongest evidence against Mr. Avery came from the victim. She identified Mr. Avery as the man who had attacked her as she jogged on a beach. She had seen his face just 8 to 10 inches from her own, she said, and had noted his height, his broad hands with stubby fingers, his hair. The first thing that had raced through her mind in the attack, she told the jury, was that she needed to "get a look at this guy."

Years after the jury found Mr. Avery guilty, his lawyers pressed to have new DNA testing done on pubic hair found on the victim after the attack. The tests revealed not only that the hair did not belong to Mr. Avery, but found that it matched another man, who had lived in the area and who had since been sent to prison for a sexual assault. The case was held up as a perfect example of how eyewitness testimony, even the best intentioned, could simply be wrong.

Even before the sexual assault conviction, Fred Hazlewood, the judge, now retired, who presided over Mr. Avery's case, said Mr. Avery's criminal record showed that he "had a real potential" for violence. "But he served his time," Judge Hazlewood said, "and you can't convict someone for what he might do."

Family members said last week that they were certain Mr. Avery was not guilty of the new charges of first-degree intentional homicide and mutilating a corpse. The authorities were wrong before, Mr. Avery's father, Al, said, and they are wrong again. The evidence, Al Avery said, was planted.

When Steven Avery finally got out of prison, his father said, he had lost his wife and family and found himself living in a tiny ice shanty once meant for winter fishing. Just surviving after so many years in prison was hard enough, Al Avery said.

"Now it's starting all over again," Mr. Avery's father said as he looked around the salvage yard that law officers had searched for days.

Mr. Avery's mother, Dolores, said she could see the way people were looking at her, again, in the grocery store and on the streets here near Lake Michigan.