Williams called Gilson, 54, the "perfect person to supervise this unit." He said Gilson was a "bulldog in the homicide courtroom" whose "investigative techniques and knowledge of the law are above reproach."
The son of a Philadelphia homicide prosecutor, Gilson has been with the District Attorney's Office for almost 27 years, 17 of them as a homicide prosecutor.
Gilson acknowledged the sensitivity of reinvestigating a conviction won by one of his former or current colleagues, but said he had tried homicide cases originally prosecuted by other lawyers in his office.
"No matter who tried the case, I'm sure everybody just wants to get it right, and that's what it's all about," Gilson said.
Gilson was the lead prosecutor assigned to one of the most difficult homicide cases in recent Philadelphia history: the 2004 trial of brothers Dawud and Khalid Faruqi for the slaughter of seven people in a crack house at 816 N. Lex St. in West Philadelphia on Dec. 28, 2000.
Gilson and fellow prosecutor Vernon Chestnut won first-degree murder convictions, and the Faruqis were sentenced to life without parole after waiving their appeal rights to escape the death penalty.
The prosecutors' biggest challenge was arguably overcoming the tainted and highly publicized history of the case, in which four men were arrested, held in prison 18 months, and were about to begin a capital homicide trial when the District Attorney's Office dropped all charges. A continuing investigation showed all four were innocent.
Williams said Gilson would work with prosecutors in the Post Conviction Relief Unit, assigned to investigate and defend prosecutions challenged under the state's Post Conviction Relief Act (PCRA).
Williams' office is investigating whether to retry two North Philadelphia men as ordered in November by a Philadelphia judge in a PCRA appeal filed by Bluestine and the Pennsylvania Innocence Project.
Judge Rose Marie DeFino-Nastasi called the evidence against Eugene Gilyard and Lance Felder "extremely weak" and said newly discovered evidence, which includes another man's confession to the 1995 slaying of businessman Thomas Keal, might acquit them.
Gilyard, 34, and Felder, 35, were arrested almost three years after Keal's slaying on the basis of a shaky photo identification by the victim's daughter. There was no other evidence.
Williams said no decision had been made about retrying the men.
Bluestine said after the news conference that she looked forward to working with Gilson and the new unit. She said the Innocence Project champions only the cases of people where there is credible evidence of innocence.
"We're not interested in freeing people who were actually involved," Bluestine said. "Conceivably, there will be cases where the D.A. has evidence that will convince us to withdraw."
Bluestine said that 33 of 87 exonerations nationally last year were initiated or brought about with the cooperation of prosecutors and law enforcement, according to a study by the National Exoneration Registry.
Bluestine cited the work of the Conviction Review Unit in Brooklyn, N.Y., by Kings County District Attorney Kenneth Thompson. Last week, she added, the Kings County prosecutor dropped all charges against a man convicted of a New York murder 25 years ago.
The man had always claimed he was at Walt Disney World at the time of the murder. Bluestine said the New York prosecutors discovered a phone bill, which had been overlooked, in one of the man's pockets that seemed to corroborate the alibi. Disney World officials subsequently confirmed that the man was a visitor.