The jury that will hear the case of Terrence G. Johnson, the 16-year-old black youth accused of murdering two white Prince George's County police officers, was chosen early this morning after two days of extensive questioning by the judge and attorneys.

Eight whites and four blacks were chosen for the jury. Seven of the whites are women. All four blacks are men. Most of the jurors are in their late 20s or early 30s.

Both alternates are white women.

After the jurors were chosen at 12:30 a.m. ending 25 hours of selection in a two day period, Circuit Judge Jacob S. Levin ordered the jury sequestered for the duration of the trial over the objection of defense attorney R. Kenneth Mundy.

The judge's order marked the first time in the memory of anyone in the courtroom that a jury in Prince George's has been sequestered -- kept under guard and not permitted to return home until a trial is complete. Jurors will be permitted telephone contact with their families.

Mundy objected on the grounds that sequestration would eliminate many of the prospective black jurors. Levin overruled the objection, saying: 'Before this trial started, it was my intention to sequester this jury. My reason for that decision was to protect the safety and well-being of these jurors. That is still my first concern."

Jury selection started Monday with an original panel of 354 jurors. That number was pared to 117 yesterday morning during preliminary questioning by Levin.

Any juror who told Levin that he had already formed an opinion about the guilt or innocence of Johnson was excused immediately. A number of other jurors who either knew the defendant or the victims, officers Albert M. Claggett IV and James Brian Swart, were also excused, as were any persons connected either directly or indirectly with any law enforcement agency.

Yesterday afternoon Levin began asking the remaining jurors more detailed questions. Among them were: Do you believe black people are discriminated against in this country? Do you believe black people are not discriminated against in this country? Do you believe black youths are discriminated against? Do you believe the police discriminate against blacks? Do you believe police are discriminated against by society as a whole?

Three persons said they believed black youths were discriminated against. No one on the panel said they believed police were discriminated against by society or themselves discriminated against blacks.

Levin then began asking questions designed to further reduce the size of the panel. He asked if anyone had been the victim of a violent crime, had been arrested, had a bad experience either with teen-agers or the police or if any of them would object to their children socializing with members of another race.

Following those questions, 97 prospective jurors remained. Several jurors were then dismissed because the judge agreed with their contentions that serving two weeks on a jury would create a hardship for them.

Three more were dismissed following defense motions, leaving 84 jurors for Mundy and State's Attorney Arthur A. Marshall Jr. to choose from.

After the 12 jurors and two alternates had been selected, one woman originally picked was excused and replaced by Levin after she began crying in the jury box. Earlier she had objected to serving on the jury.

Those chosen for the jury were immediately sequestered in a local motel.

The trial will start at 1:30 p.m. today with opening statements from prosecution and defense attorneys. The prosecution is expected to call its first witness either late this afternoon or tomorrow.