The Philadelphia District Attorney’s Office has informed a judge that prosecutors have found six boxes of files in the case of convicted cop-killer Mumia Abu-Jamal that may be significant to his appeals effort. Or, they could just be copies of existing documents.

In a Jan. 3 letter to Common Pleas Court Judge Leon W. Tucker, Assistant District Attorney Tracey Kavanagh wrote that the boxes were discovered Dec. 28, a day after Tucker ruled that Abu-Jamal can reargue an appeal before the Pennsylvania Supreme Court.

In his 36-page decision filed Dec. 27, Tucker noted that prosecutors had failed to produce two documents they were obligated to preserve while Abu-Jamal’s appeals were active. The unavailability of the documents could be prejudicial to Abu-Jamal, but the prosecutors' conduct was not egregious, Tucker said.

Kavanagh wrote in the Jan. 3 letter that the District Attorney’s Office was reviewing the contents of the six boxes and the judge was welcome to take a look, too.

Ben Waxman, spokesperson for District Attorney Larry Krasner, said Wednesday in an email that the boxes were being made available for review to Abu-Jamal’s lawyers. The letter was released to the media Wednesday.

Kavanagh explained that on Dec. 28, “the D.A. and members of his staff went to a remote and largely inaccessible room of the District Attorney’s Office marked ‘Storage,' looking for office furniture.”

They discovered the boxes, which were labeled with variations of Abu-Jamal’s name and were designated as “18/29, 21/29, 23/29, 24/29, 29/29. The sixth had no numbering."

Five of the boxes also were marked with the name “McCann.” Edward McCann was a high-level supervisor in the District Attorney’s Office who left the office in 2015.

Kavanagh wrote: “This means the Commonwealth’s prior representations that it had produced the complete file for this Court’s review in this case were incorrect, although those representations were based upon a diligent search and were accurate to the best of the Commonwealth’s knowledge at the time.”

Prosecutors had previously delivered to the court what they said was their complete file in the Abu-Jamal case, which included 32 boxes with each being marked as “1 of 31, 2 of 32, 3 of 32, etc.”

Lawyers for Abu-Jamal did not immediately respond to a request for comment Wednesday night. McCann declined to comment on the development.

In his ruling, Tucker wrote that Abu-Jamal can reargue his appeal because former Supreme Court Chief Justice Ronald D. Castille did not recuse himself due to his prior role as Philadelphia district attorney when Abu-Jamal was appealing his case.

Abu-Jamal, 64, a former Black Panther and sometime radio reporter, is serving a life sentence for the Dec. 9, 1981, shooting death of Philadelphia Police Officer Daniel Faulkner, 25, at 13th and Locust Streets.

Staff writer Chris Palmer contributed to this article