His release came at the end of a series of discoveries that his lawyers say underscores the problems of cases that rely too heavily on eyewitness identification, which studies now show often can be mistaken.
Granger was convicted and sentenced to life in prison in 1982 for the October 1980 shooting death of Edward Harris. Three eyewitnesses, including an off-duty Philadelphia police officer, testified against him.
Wednesday's release - highly unusual in the case of a life sentence - resulted from an agreement reached by the District Attorney's Office and Granger's attorneys, Karl Schwartz and David Rudovsky, who were battling to win him a new trial.
"It's unconscionable that it took 30 years for the facts to be disclosed," said Rudovsky, a veteran defense lawyer who got involved in the case on behalf of the Innocence Project of Pennsylvania.
He said the case highlighted "inherent problems" with eyewitness testimony. "The flaws in that testimony should have been shown to the jury," said Rudovsky.
For years, two of Granger's daughters worked to free him, and in 2008, they finally persuaded Schwartz, then a public defender, to take on the case.
As he went through the record, Schwartz said, he was puzzled that another eyewitness, a barmaid, was never called to testify by the prosecution.
He said he asked Common Pleas Court Judge Earl W. Trent Jr., who was presiding over the appeal, to grant him access to the homicide detectives' file. In an unusual move, the judge approved the request.
Schwartz said prosecutors vigorously opposed Trent's ruling, but he soon got to see the file. There, he found that the off-duty officer had failed to identify Granger in a photo spread - an important piece of information that could have been used to discredit the officer's critical testimony.
The defense lawyers said prosecutors then turned over from their own file the photos showing that the barmaid had identified someone else in a photo array - more information that could have helped the defense.
In addition, the defense learned that the off-duty officer had problems of his own. He had been suspended for 30 days for an off-duty shooting at a liquor store and later became a suspect in another shooting.
With such information likely to come out in a new trial, the District Attorney's Office offered a deal to Granger - plead guilty to third-degree murder and be released with no parole.
But Granger refused to plead guilty. So, after more negotiation, prosecutors agreed that if he would plead "nolo contendere" or "no contest," meaning that he was not contesting the charges, he could get out of prison.
Granger did just that earlier on Wednesday.
"I have maintained my innocence since the day of my arrest," he told Trent. "I am pleading nolo contendere to secure my freedom rather than staying in prison for years to fight this charge."
Assistant District Attorney Robin Godfrey, head of the unit that handles post-conviction appeals, disputed the defense claim that any evidence was withheld.
"We could have rebutted that claim," she said later, noting that the defense instead "chose to enter this plea" to resolve the case.
Earlier, she told Trent that a "variety of circumstances" led to Wednesday's resolution.
"We are not in any way conceding that Mr. Granger is innocent," said Godfrey, who had no involvement in the case until recently.
Schwartz had a different view.
"We have no doubt of his innocence," he said after Granger was released.
In its coverage of Granger's 1982 trial, the Philadelphia Daily News reported that Granger said that he had been on his way to a party celebrating his release from jail when Harris was killed in North Philadelphia.
Granger had said that he got out of jail three days before the shooting. According to the Daily News, he said he had been paroled after serving a sentence for rape and burglary.
On Wednesday, Granger said he could not recall the specifics of the old case, but whatever the circumstances, he said, it had nothing to do with the murder charge.
"I am definitely innocent," said Granger.
He said that the case is an example of how something "can go wrong in the criminal justice system," and that he now wants to focus on readjusting to society.
His daughter Tanya Groomes, now 37, said she and her two sisters and their mother had just finished dinner in March 1981 when police came to their South Philadelphia home and arrested her father.
"I can remember like it was yesterday," Groomes said during Wednesday's wait for her father's release.
She said that her father made good use of his time in prison - he got an associate's degree in child psychology and a high school diploma, and learned to be a brick mason. She said he also read a lot and worked on his case.
Groomes said that her father would be living with her in South Philadelphia and that there would be a party - but not until after he gets accustomed to his freedom.
Granger, who also worked in a clothing factory at Graterford Prison, said he just wants to spend time with his family.
"I believe that I'll be all right, if given a chance to recover from this," he said. "I believe I can make it."
Contact staff writer Emilie Lounsberry at 215-854-4828 or firstname.lastname@example.org.