PORTLAND — Further testing of items from the 1988 murder of 12-year-old Sarah Cherry has yielded new DNA, but it’s too early to know what the implications are for her convicted killer, Dennis Dechaine.

Dechaine is in the midst of a long-running attempt to win a new trial. To do so, he must convince a judge that a jury would not have convicted him had they known about DNA evidence found on Cherry’s thumbnail.

The latest development in Dechaine’s bid is the discovery of male DNA on the scarf that was used to strangle the girl, as well as her T-shirt and bra. The items had been tested previously in the case but were retested this summer using a scraping method that had not been employed. That DNA came from the same male, according to a report by Orchard Cellmark, the Dallas-based firm that performed the analysis.

The DNA has not yet been compared to any others samples, including DNA from Dechaine, individuals who worked on the investigation or the felons in a state database. A fresh blood sample was recently taken from Dechaine for comparison purposes.

“The thing we’re hoping for — of course, we could have it backfire on us — is that this could prove it’s not Dennis Dechaine,” said Steve Peterson, Dechaine’s court-appointed lawyer.

Dechaine, 54, is serving a life sentence for the murder of Cherry, a Bowdoin Central School student who was kidnapped while babysitting on July 6, 1988. He maintains he did not commit the crime. His defense contends the unidentified male DNA from a nail clipped from Sarah Cherry during her autopsy points to another suspect.

The prosecutor, Deputy Attorney General William Stokes, has argued that the state and jurors who convicted Dechaine already know who killed Cherry. He has described the thumbnail DNA as meaningless.

“We don’t know what it means,” he said Monday of the latest DNA testing.

The DNA from the partial thumbnail clipping was the focus of a multiday hearing in June. Expert witnesses for the prosecution testified that autopsy conditions at the time, when DNA technology was still emerging, created a high risk for contamination. But a defense witness had said contamination doesn’t appear to be an issue because the unknown DNA was not present on the other half of the nail clipping, which would have been subjected to the same handling, instrument and conditions.

Peterson said if the new DNA matches the DNA from the thumbnail, that would corroborate the defense’s position that the nail clipping was not contaminated.

The parties may reconvene for the hearing, depending on the results from the latest round of DNA testing. After the hearing concludes, Superior Court Justice Carl Bradford will decide whether the evidence warrants a new trial.

Several items were tested this summer using a relatively new scraping method to gather microscopic bits of skin cells, Peterson said. Essentially, the material is pulled taut and a razor is used to scrape the surface toward a receptacle, he said.

The front bottom and underside of the T-shirt, the inside and outside of the bra and the one end of the scarf yielded the DNA. While there was a common male donor for all three items, DNA from at least one other male found as well. The T-shirt had a mixture that appeared to be from two males and the scarf had a mixture from at least two males, according to the report.

Dechaine became a suspect after a notebook and a truck repair bill with his name were discovered in the driveway of the home where Cherry was babysitting. A search for Dechaine, then a 30-year-old farmer from Bowdoinham, and the girl ensued.

Dechaine was seen walking out woods about three miles away that day and his pickup truck was found nearby that night. Cherry’s body was found two days later, about 450 feet from where the truck had been parked. The scarf and the rope used to tie her came from the truck.

Dechaine said someone must have taken the items from his truck. He said he was injecting drugs in the woods and got lost.

Dechaine has made four unsuccessful appeals.

The Maine Legislature passed a law in 2001 giving prisoners the right to seek new trials based on DNA evidence. It revised the law in 2006 to reduce the burden on the prisoner, from having to prove that the DNA came from the real perpetrator to showing that the evidence likely would have resulted in an acquittal.

Dechaine’s current attempt for another trial began in August 2008, when Peterson filed a petition based on the change in state law.