A D.C. Superior Court jury yesterday convicted a 17-year-old Alexandria youth of the first-degree murders last year of two elderly Southeast Washington residents and of robbing and beating a third.

Gary Winston Jaggers, of 245 Burgess Ave., was acquitted by the jury of the murder and robbery of a fourth elderly victim. The jury deliberated for more than two days in the case.

Jaggers could receive a life prison term for each murder conviction. He had been charged with a series of crimes last November and December in which elderly residents of Oakwood Street SE, a once-tranquil Congress Heights neighborhood just south of St. Elizabeths Hospital, were terrorized. Jaggers also was charged with the murder of another elderly victim, for which he will be tried next year.

"No man should do to any other man or animal or object what he did," Assistant U.S. Attorney William J. Bowman Jr. told the jury in his closing arguments last week, stomping hard on the courtroom floor to indicate the manner in which Jaggers allegedly kicked to death one of the victims, Burwell M. Davis, 88, who was killed on Dec. 16.

Jaggers was convicted of first-degree murder, robbery and burglary in connection with Davis' death. He was convicted on two separate first-degree murder charges and of burglary in the Dec. 12 slaying of Julia Gambill, 65, the armed robbery of John Nelson, 80, and two counts of burglarizing Nelson's home.

Jaggers was acquitted of the Nov. 22 murder and robbery of Marie Schneck, 81, and of various rape, robbery, larceny and other first-degree murder charges in connection with the offenses for which he was convicted. He smiled as the jury foreman read the verdicts.

Defense attorneys Randy Bellows and Richard Greenlee focused much of their case on a detailed statement police said Jaggers gave them in which he allegedly implicated himself in the crimes, including the Schneck killing for which he was acquitted.

During the trial, Bellows accused D.C. homicide detectives of "psychological coercion" in extracting the statement and described what he said were numerous inconsistencies between the statement and other prosecution evidence.

"I felt he did commit all four crimes," juror Nancy Hughes said. "But I was not willing to convict him in the Schneck murder without any other evidence to support it."

"We had to take into account all of the facts," said another juror, Nicole Manly. "Since there weren't any facts to go along with the statement in the Schneck case , we couldn't put the whole verdict on that piece of paper. I don't know if I believe every single word or disbelieve every word. Where there were things to back it up, it was easier to put credence in it."

The two jurors said the jury deliberated for more than two days because of the large number of charges to consider and the complexity of the case.

During his arguments to the jury, prosecutor Bowman dismissed the defense allegations as minor and "a lot of hot air." He alleged that Jaggers' fingerprint had been found on an envelope in the home of one of the victims and that footprints made by his sneakers had been found on the head of another victim and in dust at the murder scene. He also recalled for the jury an in-court identification made of Jaggers by Nelson, the robbery victim.

" 'This is the man. I bet my life on it,' " Bowman recalled Nelson's telling the jury as he pointed out Jaggers. "Mr. Nelson doesn't know how close he came," Bowman said.

Judge Annice Wagner scheduled Jaggers' sentencing for Dec. 17. Wagner must decide whether to sentence Jaggers as an adult or a juvenile. If sentenced as an adult, Jaggers could receive a life prison term for each murder conviction and would have to serve at least 20 years before being eligible for parole. The armed robbery and burglary charges also carry maximum penalties of life in prison.

If sentenced as a juvenile, however, Jaggers could be placed on probation or receive a sentence of indeterminate length.