Pilate said that there were significant gaps and leads that weren't pursued in the original investigation and that the new information "casts very grave doubts on the government's case."
"This case is not going away," she said.
The U.S. attorney's office has said that several meetings with Pilate have yet to convince them to reopen the case.
But Pilate said Friday that she will be presenting the new information at additional meetings and that the U.S. attorney is maintaining an "open door" to hearing any new evidence.
Pilate said several newly developed pieces of information "not previously known to the prosecution" suggest that others were responsible for the November 1988 arson and explosion that killed firefighters Thomas Fry, Gerald Halloran, Luther Hurd, James Kilventon Jr., Robert D. McKarnin and Michael Oldham.
She said her investigation has concentrated on witnesses who drove by a highway construction site the night of the explosion and whose statements suggest that other people were responsible for the crime.
However, she declined to discuss specifics, noting that could influence potential witnesses and hinder the ongoing investigation by her office and the Midwest Innocence Project.
Nearly nine years after the deadly explosion, five people were convicted of the crimes: Frank Sheppard and his brother Skip Sheppard, who died in prison; their nephew Bryan Sheppard; Richard Brown; and Frank Sheppard's girlfriend, Darlene Edwards.
O'Sullivan represents Bryan Sheppard, the youngest of the defendants, and Pilate represents Edwards.
At the news conference, Pilate read portions of a statement from Marion Germann, a retired battalion chief who is the only firefighter who survived the explosions, in which he said he supports reopening the case because he knows some prosecution witnesses did not tell the truth.
"I've just always been uncomfortable with whether the right people went to trial," Germann told The Star in a 2008 interview.
In addition, for the first time, a relative of one of the fallen firefighters agreed that a new investigation may be needed.
Leo Halloran, brother of Gerald Halloran, told The Star that a new grand jury needs to consider new evidence in the case.
"That's the only way to clear all this up," Leo Halloran said.
The Star began investigating long-held doubts about the convictions in 2007. Ed Massey, who was cutting wood at the construction site around the time of the explosion, told the newspaper and later federal investigators that he saw someone set the fires that caused the explosions, but that it was not the five who were convicted.
That and other newspaper stories prompted an independent investigation by the U.S. Department of Justice that was completed in July 2011.
The department found information, not previously known to the prosecution, that suggested that other people "may have been involved in the arsons."
But Justice Department officials said the new evidence did not exonerate the five defendants who were convicted.
Written by The Kansas City Star