Alexandria's chief prosecutor told a judge yesterday that he would like another doctor's opinion on whether Gregory D. Murphy remains incompetent to stand trial in the April 19, 2000, knife attack that killed 8-year-old Kevin Shifflett.

Commonwealth's Attorney S. Randolph Sengel told the court that a psychiatrist has concluded that Murphy remains unable to assist in his defense but has shown "significant improvement" with the treatment of a new drug. During the brief hearing in Alexandria Circuit Court, Sengel told Judge Alfred O. Swersky that he would like a second opinion.

But Amy Dillard, one of Murphy's attorneys, said state law does not authorize the court to allow prosecutors to seek outside experts. She also argued that an expert chosen by the prosecution could become the state's witness.

"Anything Murphy said [to the expert] can be used against him," Dillard said.

Sengel, however, countered that another doctor, who could be appointed by the court, might offer a different opinion about Murphy's competency. The doctor also would be prohibited from reporting anything incriminating Murphy might say during the evaluation, he said. Swersky said he would rule soon on the prosecution's request.

Murphy, who suffers from paranoid schizophrenia with severe delusions, has been receiving antipsychotic medication at Central State Hospital in Petersburg, Va., in an effort to restore his competency. Status hearings on his progress have been held every six months since he was found incompetent to stand trial in Shifflett's slaying.

In her latest report to the court, Lillian M. Tidler, the assistant facility medical director, said the new drug, Abilify, and Murphy's other medications have resulted in "an improved mood, being more alert and overall has evidenced improvement to sustain his attention, express himself verbally with more clarity."

Although Murphy is not now considered competent to stand trial, Tidler said in the report that she is optimistic that "he may experience further improvement in the next few months." But she also said Murphy "continues to have deep mistrust for his attorney secondary to his underlying symptoms of paranoid delusions, despite his insistence that he is willing and desires to cooperate with them."

Murphy, who was wearing restraints, looked on calmly during yesterday's hearing but was not allowed to sit with his defense team. His first attorney, Jonathan Shapiro, was removed from the case after Murphy assaulted him in the courtroom, knocking him unconscious. At another hearing, Murphy asked the judge to appoint Johnnie Cochran, the former O.J. Simpson attorney, to represent him if he is tried on a charge of capital murder.

It has been more than four years since Shifflett was stabbed 18 times while playing in the front yard of a relative's home in the Del Ray section of Alexandria. Shifflett was killed 12 days after Murphy was paroled from prison in April 2000.

Murphy served more than six years in prison for attacking a stranger with a hammer and other crimes. He was staying with his family in Del Ray, a few blocks from where Shifflett was playing with friends and siblings, after he was paroled.

The unprovoked attack on a child shocked the Washington region and led to a massive hunt for the killer. After the attack on Shifflett and the wounding of a good Samaritan who tried to help the boy, the assailant was seen hopping into a cab to flee.

Gregory Murphy has shown significant improvement with a drug, a psychiatrist's report said.