Advocates for Latinos accused Prince George's County State's Attorney Jack B. Johnson yesterday of botching the prosecution of a Laurel teenager accused of killing a Salvadoran immigrant.

One advocate, Bill Stagg, director of the Hispanic Resource Center and a retired county police officer, suggested that Johnson did not prosecute Cochise Iraun "Cody" Queen, 18, as vigorously as he could have either because of political considerations related to the ethnicity of the victim and the race of the alleged killers, or "gross incompetence."

"Maybe Mr. Johnson is trading future votes for justice," Stagg said, alluding to Johnson's widely anticipated campaign in 2002 for county executive. Queen and the two other alleged attackers are black, and Stagg speculated that Johnson may not be prosecuting them more vigorously out of fear of losing some support among black voters.

The criticism came one day after county prosecutors switched their legal theory of how the crime occurred and argued to the jury that Gilberto Hernandez, 40, was killed during a robbery--legally a felony murder--the same scenario that Johnson previously had discredited.

The plea for a felony murder conviction was first presented in the trial's closing arguments, after jurors originally were told throughout the three-day trial that there was no motive for the Sept. 4, 1998, attack.

Queen was convicted by a Circuit Court jury late Wednesday of involuntary manslaughter and two counts of second-degree assault. He was acquitted of the more serious charges of felony murder and second-degree murder.

Although the judge in the case ruled that the jury could consider felony murder, a juror said after the verdict that he and other jurors did not believe there was enough evidence of a robbery to convict Queen of felony murder.

Johnson did not return phone calls seeking comment yesterday. His office released a statement saying, "The jury has spoken, and the state's attorney has nothing else to say."

But in a post-verdict interview with WRC-TV (Channel 4) Wednesday night, Johnson accused others of trying to trade on the race issue.

"We understand that any time in this country when there's a cross-racial killing, it creates fear and distrust," Johnson said. "But I think many people, unfortunately in this case, exploited that, and that's why it created such a sensation."

Although two witnesses, including one of Hernandez's brothers who was present when the fatal attack began, testified at the trial that the attack began as a robbery, Johnson has adamantly maintained for nearly a year that there was no evidence of a robbery. A law enforcement source has said that another of the teenagers involved in the attack also told Laurel police that it began as a robbery.

Johnson declined to charge Queen and co-defendants Kellie Day Martin, 19, and Steven Darby, 17, with robbery and first-degree felony murder, which carries a potential life sentence.

Instead, the three originally were charged with common-law murder, which includes first-degree premeditated and felony murder, second-degree murder, and voluntary and involuntary manslaughter. Assault charges were added later.

During a news conference yesterday at a county community police station in Langley Park, Stagg and other activists for Latinos praised the investigation of the slaying by Laurel police and the work of prosecutors Fran Longwell and E. Wesley Adams, who prosecuted the case in court.

But they renewed their criticism of Johnson for deciding not to interview Juan and Tomas Hernandez, who were with their brother when he was attacked, until seven months after charges were dropped against four other teenagers in exchange for their trial testimony.

Carmen T. Joge, senior civil rights policy analyst for the National Council of La Raza, said: "I think this case was pretty much doomed from the beginning, given that the prosecutor maintained from the start there was no motive, making the case substantially weaker.

"It seemed from the beginning that they didn't want anything to do with the witnesses and wanted to take the word of the youths [who had been charged]. I'd be worried if I were ever to become a victim that the prosecutor would take the word of the assailant over mine," Joge said.

CAPTION: Gilberto Hernandez's brothers Juan, left, and Tomas, sister Maria and brother Santos, appear at a Langley Park news conference. Gilberto, a Salvadoran immigrant, was killed in September 1998, and an 18-year-old Laurel man was convicted Wednesday of involuntary manslaughter and assault.