The charge was murder. But when the Laurel teenager was tried two weeks ago in the highly publicized slaying of Salvadoran immigrant Gilberto Hernandez, Prince George's County prosecutors presented evidence that pointed to lesser crimes: involuntary manslaughter or second-degree assault. And those are the crimes the jury convicted him of on Oct. 6.

Since the Hernandez slaying last year, the case has provoked a heated public response (See Letters to the Editor, Page 4.) and has caused many area lawyers to say they are puzzled by the strategy used by the office of State's Attorney Jack B. Johnson, the county prosecutor. The lesser charges carry maximum sentences of 10 years each; a felony murder conviction (such as for a slaying committed in the course of a robbery) would have allowed Johnson to seek life in prison for defendant Cochise Iruan "Cody" Queen.

The testimony in the trial of Queen, 18, also suggested that there may be trouble ahead as Johnson's office attempts to win convictions against two other defendants who are to go on trial next month in the Hernandez slaying.

Three prosecution witnesses who were granted immunity in exchange for their testimony admitted in the Queen trial that they lied to the police or to a grand jury. So their credibility in any future trials may be called into question--and that could make it harder to convict other defendants.

Johnson, who in recent months has declined to comment on the Hernandez case, did not respond to a request for an interview for this story.

Legal observers said the verdict in the Queen trial was not surprising, given the way prosecutors presented the case.

A former prosecutor, who did not want to be identified, said that the prosecutors hurt their case by telling jurors that there was no motive for the attack at the outset of the case, then asking them in closing arguments to convict Queen of felony murder because the assault began as robbery. If prosecutors had succeeded in their late trial move, Queen could have received a life sentence. He will be sentenced Nov. 5 and may have to serve only a third of his sentence.

"They got the outcome they wanted," the former prosecutor said.

"Switching theories at the end of a trial is very unusual. It sends a mixed signal to jurors," said Patrick J. McAndrew, a Beltsville criminal defense lawyer.

Some lawyers speculated that Johnson could take a different tack in the upcoming trials in light of a finding by Circuit Court Judge E. Allen Shepherd that there was credible evidence that the attack began as a robbery. The lawyers speculated that Johnson may direct his prosecutors to pursue the felony murder more zealously when defendants Kelly Day Martin, 18, and Steven Darby, 17, go on trial next month.

The prosecution's initial decision against seeking a felony murder conviction flowed from Johnson's longtime assertion that the Sept. 4, 1998, attack did not begin as a robbery. This was contrary to the findings of the Laurel police and statements or testimony by at least three witnesses.

In his opening statement in the Queen trial, Assistant State's Attorney E. Wesley Adams told jurors that there was no explanation for the attack on Hernandez, whose skull was cracked when Queen tackled him football-style and the victim flew into the air and landed on his head, according to testimony.

Using the same language that Johnson has used in describing the attack, Adams said the assailants wanted to "mess with" Hernandez. Prosecutors contend that after Queen tackled Hernandez, Martin then kicked the helpless Hernandez so hard he suffered another skull fracture.

After prosecutors had finished presenting their case, defense attorneys Steven M. Jacoby and Paul S. Christian asked Shepherd to acquit Queen of first-degree premeditated murder and felony murder charges, arguing that prosecutors had presented insufficient evidence to sustain those charges.

Shepherd threw out the first-degree murder charge but let the felony murder charge stand, noting that a prosecution witness, Mark Ramsay, had testified that he heard Martin suggest a robbery moments before the attack began. Juan Hernandez, Gilberto's brother who ran away from the attackers and escaped injury, also had testified that the assault began as a robbery.

Then, in an abrupt shift, Assistant State's Attorney Fran Longwell urged jurors to convict Queen of felony murder, citing the testimony by Ramsay and Juan Hernandez.

Another problem for prosecutors is the testimony of witnesses who originally were charged by Laurel police with robbery and murder but had those charges dropped by Johnson in exchange for immunity and their testimony against Queen, Martin and Darby.

Their credibility appeared to be severely undercut during aggressive cross-examinations by defense attorney Christian, raising questions as to why Johnson found them more credible than the surviving Hernandez brothers, who he has said are not credible witnesses.

Three of the four immunized witnesses admitted lying about what happened the night of the attack to either Laurel police or a Prince George's County grand jury.

For example, Gerald Culbreath, 16, admitted on the witness stand that he lied to Laurel police when he told them another teenager--who wasn't involved in the attack--kicked Hernandez. And David Eugene Burley Jr., 20, testified that he lied to the grand jury when he blamed the attack on a teenager who did not participate in it.

In rejecting the conclusion of Laurel police detectives that the attack began as a robbery, Johnson decided to rely heavily on the testimony of the former suspects.

Ralph Warren, a Capitol Heights lawyer and a former deputy to Johnson, said the fact that key prosecution witnesses have admitted to lying to police and the grand jury "will have devastating consequences for the prosecution. If you lie about one thing, you can lie about something else, and jurors will take that into account."

"The prosecution has now shown its hand, and defense counsel [for Martin and Darby] will be prepared to cross-examine them," said Warren, who was one of two deputies to Johnson until he resigned in the summer of 1998, after Johnson actively opposed his candidacy for a District Court judgeship.