PORTLAND — Dennis Dechaine’s legal team has the odds stacked against it in the convicted murderer’s attempt to use new DNA analysis to win a new trial.

Dechaine, a Bowdoinham farmer, was convicted of murdering 12-year-old Sarah Cherry of Bowdoin in 1988. Dechaine is serving a life sentence at the Maine State Prison for the crime. He and an ardent group of supporters contend that he is innocent and have for years sought a new trial.

In 2006, in no small part because of Dechaine’s repeated appeal attempts, the Legislature enacted a law regarding new DNA evidence that requires defendants to prove that the evidence could only have come from the perpetrator of the crime. Based on testimony during a two-hour hearing Thursday in Cumberland County Superior Court, the new DNA evidence didn’t appear to match that threshold.

Steven Peterson, Dechaine’s attorney, who has acknowledged to the Bangor Daily News that the burden put on Dechaine by the law is high, said he will take his argument for an appeal to the Maine Supreme Court if he has to.

Because of the small sample sizes of biological matter from Cherry’s fingernails, clothing and a scarf that was used to strangle her, as well as the fact that the DNA has degraded over the years, DNA expert Rick Staub said the evidence could neither prove nor disprove the guilt of Dechaine or an alternative suspect who was identified by Dechaine’s legal team. The Bangor Daily News is not naming that suspect, who now lives in Florida, because he has never been charged in connection with the case. In addition, Justice Carl O. Bradford, who has presided over the case since 1989, has never allowed the introduction of an alternative suspect theory.

William Moore of Brunswick, who is a private investigator working on the Dechaine case, traveled to Florida in 2006, where, according to his testimony Thursday, he acquired the alternative suspect’s DNA after looking through the man’s trash and confiscating a coffee cup the man allegedly used at a diner.

“From my research when I started looking into the case, he was the number one alternative suspect in the case from Day One,” said Moore. “We asked him for (his DNA in 2004) and were denied. We determined that the only way to get it was to follow him around.”

Moore shipped the coffee cup to a DNA analysis firm in Texas called Orchid Cellmark, which compared it to matter found on Cherry’s shirt, bra, scarf and fingernails. The analysis determined that DNA from at least two adult men were found among the evidence and that neither Dechaine nor the alternative suspect could be excluded as the source.

Peterson said that even though the evidence is not conclusive, it could well lead to a different outcome for Dechaine, particularly given the fact that Dechaine’s DNA was not found under Cherry’s fingernails.

“This is the very kind of thing that a jury would consider to be reasonable doubt,” said Peterson to reporters outside the courthouse. “We’re talking about an alternative suspect that can’t be excluded.”

Peterson said the hearing would continue on Friday with more DNA experts as well as a witness from the Innocence Project, an organization that seeks to free wrongly convicted people based on DNA evidence. The state will have an opportunity to rebut Peterson’s presentation Friday.

Dechaine is hoping new DNA analysis in his case will be enough to convince Bradford to grant him a new trial. That decision is not expected to be rendered on Friday, but rather in a written decision sometime in the future.

Thursday’s hearing was delayed several hours because Dechaine had not been transported to the courthouse by its original start time.