Mr Anthony Ray Hinton, was set freed after spending 30 years in prison.
Tests on bullets found at the crime scene could not be connected to a gun found at Mr Hinton’s home, prompting prosecutors to drop the case.
His lawyer, Bryan Stevenson, said his client was convicted because he could not afford better legal counsel.
Walking out of the Jefferson Country Jail in
Birmingham, Mr Hinton hugged family members and said: “Thank you, Jesus.”
“All they had to do was test the gun,” Mr Hinton said, explaining why he shouldn’t have had to sit on death row for nearly three decades.
Bullets from the crime scene were the only evidence that linked Mr Hinton to the murders.
Prosecutors said that modern forensic methods failed to link the bullets to a revolver found in Mr Hinton’s home.
“Every day, every month, every year that the state took from him, they took something that they don’t have the power to give back,” said Mr Stevenson.
At his first trial, Mr Hinton’s lawyer believed his client only had $1,000 (£670) to hire an expert that could defend against the prosecution’s allegations about the bullets.