The case had grown to include nearly 800 witnesses and 7,000 pieces of evidence at one point, including a poster of Guns N’ Roses singer Axl Rose, history books and an academic thesis about Chilean anarchists.

But the government’s plans to try them for terrorist conspiracy, punishable by up to life in prison, fell apart after a judge threw out 70 percent of the evidence as flimsy or irrelevant, and ordered prosecutors to pay the legal fees of suspects who had sustained a 65-day hunger strike while in maximum security prison.

An appeals court then upheld the judge’s ruling, leaving prosecutors with no alternative but to drop the charges filed under Chile’s dictatorship-era anti-terror law, which allows for the use of secret witnesses, lengthy pre-trial detention and other stiff measures.

Four of the suspects still face charges of setting off a total of 29 bombs and two others for allegedly financing the criminal acts. All six were freed pending a Nov. 28 trial.

The investigation had gone nowhere for years until Interior Minister Rodrigo Hinzpeter put an aggressive prosecutor, Alejandro Pena, in charge.

Two months later, he announced charges involving 120 noise bombs — artifacts with little explosive power that cause enough noise to break windows — that were detonated outside financial institutions from 2006 to 2010. Only one person died in these attacks, a young man whose bomb exploded in his backpack.

Defense Attorney Mauricio Daza told The Associated Press that he has no doubts that his firm’s client Francisco Solar, who was jailed after his doctoral thesis was found in another suspect’s apartment, will ultimately be found innocent of the remaining charges, involving two of the bombings in his case.

Deputy Interior Minister Rodrigo Ubilla said he doesn’t consider the terror case to be a failure.

“We are not going to be inhibited from completing our role. The evidence was there, we put it before the pertinent authorities, and if they decided it wasn’t a crime, that’s a situation we don’t manage,” Ubilla said.

But Chile’s top prosecutor, Sabas Chahuan, who named Pena to the case at Hinzpeter’s request, declared Tuesday that he would ask for a detailed investigation into what, if anything, went wrong.