PORTLAND - Daniel Roberts appealed his murder conviction Thursday to Maine's highest court, saying the trial judge erred on several counts.

Thomas Marjerison argued Roberts' case before the Maine Supreme Judicial Court at Cumberland County Courthouse.

Roberts was found guilty about a year ago of shooting his ex-girlfriend in the back of the head at close range in his garage early in the morning on Aug. 15, 2005. He said Melissa Mendoza, 29, had come to his Sabattus home threatening to kill their 2-year-old daughter, Savanna, and him.

Androscoggin County Superior Court Justice Joyce Wheeler sentenced Roberts to 55 years in prison.

In his allotted 15 minutes, Marjerison focused on the three points of appeal "most harmful" to his client.

A photograph shown to the trial jury by Deputy Attorney General William Stokes served no purpose other than to prejudice jurors against Roberts, Marjerison said.

"It bore no relevance to (Roberts') credibility or state of mind," Marjerison said.

Stokes, during his 15 minutes, countered that Roberts had opened the door, figuratively, by saying that Mendoza told Roberts she was going to kill her baby, the same one pictured in the close-up photo depicting a loving mother kissing her child in a serene moment.

The photo "puts in context exactly what (Roberts) is saying," Stokes told the judicial panel.

Justice Donald Alexander asked how old the photo was at the time of the trial. Stokes said the baby was about a year old. She was 2 years old when her mother was shot dead.

"A year can make a lot of changes in people's lives," Alexander said. Stokes said it was a fair representation of the two at the time of the shooting.

"Wasn't it just a play for sympathy?" Alexander asked.

Stokes said, "No," it showed a real relationship between the two.

On another point of appeal, Marjerison said a sworn affidavit by Mendoza for a protection from abuse order filed shortly before she died was "really damaging to my client" and should not have been allowed to be given to the jury because it violated Roberts' constitutional rights.

Chief Justice Leigh Saufley said Roberts' trial lawyer, Leonard Sharon, could have objected when it was introduced by prosecutors, but he didn't.

Saufley asked how many protection from abuse orders in total were given to the jury, then pointed out that two of the three had been supplied by the defense.

Justice Alexander noted the reams of documents introduced as evidence during the three-week trial. "This is kind of like a needle in a haystack," he said.

Stokes said the affidavit was used to explain Mendoza's actions, not to prove what Roberts did.

Wasn't it possible to explain her actions without her affidavit, which suggests violent acts on Roberts' part? Justice Jon Levy asked.

Marjerison's third point of appeal centered on instructions given to the jury.

He said the jury should have been asked whether Roberts knew Mendoza did not pose a threat of physical harm to him and their daughter. Instead, the jury was asked whether Roberts believed Mendoza posed that threat.

Stokes said the self-defense justification, as used by Roberts, is based on a person's beliefs at the time of the act.

The five-member panel also was given written arguments by the state and the defense, covering other grounds for appeal. The court is not expected to rule on the matter before this summer.