Jury selection began Monday in the trial of John A. Wagner, a 34-year-old city man accused of killing a Johns Hopkins researcher last year.

Wagner is charged with first-degree murder in the stabbing death of 23-year-old Stephen Pitcairn, who police say was robbed at knifepoint as he walked from Penn Station to his home in Charles Village the night of July 25, 2010. The killing angered the city and became a campaign issue in the race for city state's attorney.

Baltimore Circuit Judge Charles J. Peters told the jury pool of 130 that he anticipated an eight-day trial that would end about Aug. 17.

Choosing a jury proved challenging: More than 80 of those called Monday said they could not serve for that length of time. Nearly a third said their philosophical, moral, ethical or religious beliefs made it impossible for them to render a fair and impartial verdict, and 43 said they had knowledge of the crime through intense media coverage. However, Peters said no one would be dismissed until a 12-person panel and several alternates were seated.

In pretrial motions, Wagner's attorneys said they believe that many potential jurors, if not all, had heard something about the case. They asked the judge to include questions about Charles Village, the location of the crime, and to include the fact that a knife was used in the crime in his questioning of the pool.

"If there are not enough facts provided upfront, many will not realize that they do have prior knowledge," said Greg Fisher, Wagner's court-appointed attorney.

During questioning, 50 said their strong feelings about a robbery and homicide that involved use of a knife would make it difficult for them to weigh the facts impartially. Another 13 said they had resided or were residents of Charles Village.

Fisher also asked that the judge query the potential jurors for racial bias — Pitcairn was white and Wagner is black. When Peters asked whether race would affect anyone's ability to be fair and impartial, not a single potential juror stood up, which would have signaled a "yes" reply.

Wagner's shackles were removed before potential jurors entered the courtroom Monday. He wore a khaki suit and a tie.

Several of Pitcairn's co-workers were in the courtroom, but declined to comment. Pitcairn's mother, who was speaking with her son on the phone at the time of his death, is expected to attend the trial and may be called to testify, officials said. Other relatives are expected to arrive from Florida for the trial.

Lavelva Merritt, 23, who was initially charged along with Wagner in the killing, is also expected to testify. Prosecutors agreed to drop murder charges against her in exchange for her testimony against Wagner, who was her lover at the time of the crime. She has pleaded guilty to robbery and conspiracy.

