A court-appointed psychologist testified yesterday that Latrena Pixley, the District woman who was convicted of killing her infant daughter seven years ago, should not be granted custody of her 3-year-old son, Cornilous, because she remains emotionally unpredictable despite signs of progress in her mental health.

Instead, clinical psychologist John B. Mealy said he would recommend that Laura Blankman, 29, a Montgomery County police officer who has raised the boy since he was 3 months old, should be granted legal custody of the child and Pixley, 26, should be allowed to continue visiting him.

Mealy sat at the witness stand for nearly all of the first day of arguments in the second trial held to determine which woman should raise Cornilous. In the first trial, in 1997, a Montgomery County Circuit Court judge ruled that Pixley should be given custody of the boy despite her guilty plea to second-degree murder in the smothering death of her 6-week-old daughter, Nakya. The Maryland Court of Appeals this year remanded the case to Circuit Court, ordering the lower court to determine whether there is any likelihood that Pixley would abuse or neglect Cornilous if she is given custody.

Yesterday, Mealy testified as an expert witness that he believed there is indeed a risk that Pixley would neglect the child, and therefore recommended that Blankman be given full legal custody. He was the first in a series of witnesses who are expected to take the stand in the case this week before Circuit Court Judge Louise G. Scrivener, who is new to the case, makes a ruling on the issue of custody.

Mealy, who interviewed and observed both women, as well as Cornilous, during numerous meetings between July and September, said Pixley's interactions with her son were caring and affectionate during their meetings with him. He said he believed she was making a recovery of her own from years of abuse she suffered as a child. But, he noted, it's a recovery in progress.

"She's in the process of recovery, but the early stages of it. So it's unpredictable," he said, adding that he found her to suffer from faulty judgment and impulsive behavior. And, he said, there still are strong antisocial tendencies in her personality. Those factors, he said, could lead to the child being neglected, though he did not believe Pixley would abuse him.

In addition, he said, Blankman has become Cornilous's primary attachment, even though the little boy calls both women "Mommy" when he's with them. The ideal would be for both women to stay in Cornilous's life. "I think he could sustain both relationships under these conditions."

Ralph Hall, one of Pixley's two attorneys, challenged Mealy's conclusion that there is a possibility of neglect if she is granted custody. Hall spent much of the afternoon trying to poke holes in Mealy's testimony and in his clinical testing methods. Outside the court room, he said he will call expert witnesses who will testify that they believe Pixley would not be a neglectful parent.

Hall said Pixley has sought to better her life in recent years. She has taken parenting classes and steadfastly sought employment, he said, adding that finding work had become difficult for her because of her notoriety. "She's a different person than she was in 1997," he said in his opening statement, later telling the court: "Most important, you will hear how much she loves and cares for her son."

And Hall also said this case was in part about race: Blankman, who is white, he said, would not be as well suited to raising an African American child as would his birth mother.

In the 1997 case, Circuit Court Judge Michael D. Mason ruled that Pixley should have custody of Cornilous because it was in the best interest of the child to be with his biological mother, and because Pixley had maintained contact with him even while she was jailed. Mason also said that a less important reason was that Cornilous, who is black, would be better off with an African American mother.

Mason's ruling drew widespread public criticism and focused attention on Maryland laws that strictly protect the rights of biological parents. Mason's decision was upheld last year by the Maryland Court of Special Appeals.

Yet the state's highest court, the Court of Appeals, ruled this year that Mason's finding that Pixley did not pose a threat of death or abuse to Cornilous was not sufficient to grant her legal custody. The Court of Appeals decision sent the case back to Circuit Court to determine if Pixley poses a risk of abuse or neglect.