Donna Best Hoffmann, 19, did not know that her boyfriend and four other young men planned to kill her husband when she drove him to an isolated spot in Aquasco, Md., on Dec. 15, Hoffmann's defense attorney, Karl Feissner, told the jury yesterday in his opening statement in Prince George's County Circuit Court.

Hoffmann is charged with first-degree murder and accessory after the murder for her role in the execution-style shooting of Michael Hoffmann, 20, her husband of three months and a civilian clerk at Andrews Air Force Base.

The prosecution maintained yesterday that Hoffmann helped five others plan the shooting, that she drove her husband to the lonely road in Aquasco, where she got out of the car with her husband and then watched as George Bernard Harvey, 23, shot him in the chest and head.

Assistant States Attorney Michael Whelan told the jury that Hoffmann paid Harvey $100 immediately after the shooting. "You will have never heard a more bizarre story in any courtroom in the country," Whelan told the jury.

Feissner, a private attorney hired by the public defender's office to represent Hoffmann, argued in his opening statement that the plan to murder Michael Hoffmann was devised by John Penkert, Hoffmann's 26-year-old boyfriend. He said Donna Hoffmann was unaware of Penkert's plans. The motive behind the plan, Feissner said, was love.

"Penkert had a fixation in his mind," Feissner told the jury. "He couldn't live without this young lady."

Feissner admitted yesterday that Donna Hoffmann was present during one meeting at which the young men were planning the slaying, but he said Hoffmann was not fully aware of what was being discussed.

"Whenever she would hear them, she would be 'shushed' away or told to get a glass of water from the kitchen," Feissner said. He did indicate, however, that Hoffmann might have understood that the men were planning to harm her husband. "Penkert told her, 'Don't worry, after today you'll be all mine,'" Feissner said.

Hoffmann looked quite different yesterday from her initial appearance in court on a bond hearing after her arrest. At that time, she wore a shapeless dress. One sock had fallen to her ankles. Her blond hair was scraggly, and she wore no makeup. Yesterday, Hoffmann wore a white dress with ruffles along cap sleeves. Her cloth belt was tied in a bow around her waist. She wore nylon stockings, and her hair was neatly curled. She wore mascara, eye liner and a touch of rouge.

Whenever Hoffmann accompanied her lawyer to the judge's bench, she kept her hands clasped, under her chin. Occasionally, she sighed deeply, although she showed no emotion when Penkert entered the courtroom.

Donna Hoffmann's parents attended the trial yesterday, but Michael Hoffmann's father and brothers did not.

The five young men charged in the case each have pleaded guilty to first-degree murder, but they have not been sentenced. One of them, Jeffrey Scott Whittaker, a former student at Johns Hopkins University, definitely will testify against Hoffmann, and the others may testify against her, Whelan said.

Whittaker was the first to plead guilty and received a plea bargain arrangement whereby he would testify against other defendants in return for a light sentence. Whelan has recommended to the court that Whittaker receive a life sentence with all but 15 years suspended.

The other defendants have received recommended sentences from life with all but 40 years suspended to life in prison.

For nearly six hours yesterday, Judge Jacob Levin questioned 200 prospective jurors about whether they had read about the case in the newspapers and whether the articles had influenced them. About a quarter of the jurors were disqualified because they admitted they might have been influenced. Eventually, lawyers chose a jury of seven men and five women, most of them middle-aged and elderly.