CHICAGO (WLS) -- Anthony Porter's release in a 1982 double murder case was considered the one that started the momentum to end the death penalty in Illinois.
When ABC 7's Charles Thomas interviewed Porter last April, he feared that Alstory Simon would be released and he would be imprisoned again.
"I'll tell the truth, it scares the hell out of me," Porter said in the interview. "It's like a nightmare, like a cycle that keeps going 'round and 'round."
But State's Attorney Anita Alvarez says that under double jeopardy rules, Porter cannot be re-tried.
"Anthony Porter's not looking at any other charges. I couldn't even if I wanted to indict him," Alvarez said.
Porter was freed in 1999 after 16 years on death row for a 1982 double murder. He became the poster boy for wrongful convictions after Simon confessed to the crimes on videotape for Northwestern University's innocence project.
"I just pulled it out and started shooting," Simon said in the taped footage.
But during a news conference Thursday, Alvarez called the case against Simon, who recanted his confession, "corroded and corrupt."
"The antics of a rogue investigator and a professor," she said.
Alvarez says the re-investigation revealed that private investigator Paul Ciolino, students and at least one armed man impersonating a law enforcement officer barged into Simon's apartment and showed the suspect tape of an actor impersonating an eyewitness.
"If any law enforcement ever did that, courts would be screaming about the conduct," said Terry Ekl, Simon's attorney.
Former Gov. George Ryan, who cited the Porter case when he suspended executions in the state, remains a death penalty opponent while applauding the decision to free Simon.
"If they've made that decision then I guess justice is being served," Ryan said.
"God knows in heaven that I'm innocent," Porter said.
Alvarez says after the re-investigation, she cannot be 100 percent sure who committed the murders, but said, "there are compelling facts from eyewitnesses who were there at the scene that maintain to this day that it was Anthony Porter that did the shooting."
The Campaign to End the Death Penalty issued a statement Thursday saying Simon's release is "an attack upon the integrity of justice."
Alvarez said there will be no legal action taken against former Northwestern journalism professor David Protess, who headed the Innocense Project at the time, or Ciolino, as the statute of limitations has expired on any crimes they may have committed.