Nelson told Judge Richard J. Walsh that the amended post-conviction relief act that went into effect in January 1996 provided a one-year grace period for old cases.
According to court records, Rock didn't file the petition until May 1997.
"Mr. Rock has responded by saying he comes within statutory exemptions," Nelson told Walsh.
"I began investigating, I believe in 1995, the possibility that evidence was concealed in the second trial," Rock said on the stand.
Thin, balding and wearing an orange county prison uniform, Rock was brought here this week from the Huntingdon State Correctional Institution, where he is serving consecutive life sentences.
Rock said he filed late because it took more than a year to gather and review court transcripts.
Under questioning from Nelson, Rock said no government official tried to obstruct his access to information.
"The Commonwealth has never acknowledged that evidence was suppressed in the 1978 trial," Rock said. He contended that because discrepancies in the testimony of a state trooper were never resolved, the grace period should be waived.
"The facts upon which he is basing his argument have been known for years," Nelson said.
Trooper Randy Kepnure, now deceased, testified in the 1978 trial that he took soil samples showing Rock made gasoline trails to set his Fayetteville cabin on fire from a safe distance. At a 1982 federal court hearing, Kepnure testified soil samples were taken near a utility pole.
"I believe the reason he took it there was because he knew it would come up positive" due to petroleum-based wood preservatives on the pole, Rock said.
Before his second trial, Rock said his attorney failed to file a motion to dismiss the charges because his first conviction was due to prosecutorial misconduct.
Nelson said a 1992 state Supreme Court ruling, Commonwealth vs. Jay Smith, could not be applied to Rock's second trial in 1985. He said defense attorney David Rudovsky "should not be held to the standard in 1984 and 1985 to predict constitutional questions in 1992."
Rock said Oregon vs. Kennedy, a 1982 U.S. Supreme Court ruling, covers his case.
Nelson said the court ruled in that case that a defendant could not be retried because prosecutors deliberately tried to create a mistrial.
"My contention is, your honor, the Supreme Court established a law for prosecutorial misconduct" broad enough to cover his case, Rock said.
Rock's defense in both trials was that he was insane when he shot Brookens and Cutchall as they arrived at his burning home.
Walsh made no ruling, giving Rock and Nelson 30 days to file legal briefs.
A member of the Fayetteville fire company attended the hearing, but declined to comment.