At the public defender's office, James Grayson, who was convicted of murder in 1964, left with his fiancee, whom he said he intends to marry soon.
"I trust in God, and he's first in my life," Grayson said. "He opened this door for me."
Prosecutors said the victim's family in Grayson's case understood it was time for him to be free.
But Kevin Magrogan, whose brother, Thomas Magrogan, was killed in 1971, said before the hearing he planned to ask the judge to retry the last of the men, Bryant Lee Goodman, because a witness is still alive.
In court, Magrogan, a retired Baltimore County police officer, abandoned that strategy, instead questioning the wisdom of the release. He pointed to drug-related rules violations on Goodman's prison record.
In his old job, Magrogan had been able to arrange to see Goodman sitting in his prison cell in the 1970s.
"There was no other place for him," he said after the hearing.
Goodman was the only defendant who spoke in court. He said he was "truly sorry" for what happened to Thomas Magrogan and had dwelt on his crime for the 42 years he had been in prison.
"I don't think there has been a day gone past I haven't thought about that particular day," Goodman said.
The Maryland Court of Appeals ruled last year that standard jury instructions before 1980 led to unfair trials. Judges had told jurors they were supposed to consider what the law means, rather than simply the facts of a case. The high court decided in 1980 that such directions were defective because they robbed defendants of their right to be proved guilty beyond a reasonable doubt. But it was not until last year that the court said the concern was significant enough to warrant new trials.