A D.C. medical examiner testified yesterday at the murder trial of 10 young persons that one of victim Catherine L. Fuller's injuries was so severe that it was the kind typically suffered only in a high-speed car accident or in a fall from a building.

Dr. Michael P. Bray also told a D.C. Superior Court jury that Fuller died of numerous blows of various kinds -- a key prosecution contention -- and that had she survived, her treatment would have been a "nightmare."

"What you're talking about is a woman who received multiple blunt-force injuries of various types," said Bray, before reciting an extensive list of injuries discovered during an autopsy of the 99-pound Fuller. The injuries included brain and facial wounds, broken ribs, a pierced rectum wall, and numerous lacerations and abrasions over much of Fuller's body.

When Assistant U.S. Attorney Jerry S. Goren asked Bray to describe the state of Fuller's liver on Oct. 1, 1984, murmurs reverberated throughout the otherwise somber courtroom as Bray said the organ was "basically shattered."

"The amount of injury could be produced only by great force . . . , " Bray said. "It is the type of injury seen most prominently in high-speed motor vehicle accidents and in people who jump off buildings."

Bray later said Fuller's liver also showed unrelated signs of cirrhosis of the liver -- "consistent with the chronic use of alcohol" -- and that the alcohol level of her blood at the time of her death was twice the legal intoxication level.

Later, jurors winced and shook their heads as they quickly passed along their two rows snapshot-sized color photographs of Fuller's body. One juror closed his eyes and repeatedly blew air into his cheeks. Another glanced at the pictures and then stared at the 10 accused sitting in two rows.

During testimony by Bray, the last government witness expected to be called to the stand, some of the defendants bowed their heads while several leaned forward to follow the paths of injury he charted on diagrams.

Several eyewitnesses have testified during the last three weeks that Fuller was beaten and kicked to death and a pole thrust into her rectum, after she resisted an attempt to steal her coin purse. Only one of the accused, 17-year-old Felicia Ruffin, has not been named in testimony as a participant in the beating. One witness said Ruffin was standing in the abandoned garage where Fuller was assaulted and received a ring, which the prosecution contends was stolen from the victim.

In the District, a person can be convicted of felony murder -- one of the charges lodged against all 10 defendants -- if he or she participated in or aided a felony, in this case armed robbery or kidnaping, that led to a death.

Earlier in the day, a police detective told the jury he had overheard two of the accused discussing Fuller's death in a holding cell soon after their arrest.

"Christopher Turner was telling Bobo Russell Overton not to worry about anything because the police didn't have enough to charge them . . . " said Detective Daniel Villars, who said he was guarding the two men at the time, "because they didn't touch the body and the police didn't recover their fingerprints."

The prosecution contends that the statement implicates the two men in Fuller's death, but under cross-examination defense lawyer Allan Palmer attempted to show that Villars may have misinterpreted the conversation.

In another proceeding, Judge Robert M. Scott said he had reconsidered an earlier decision and decided to allow the jury to see a police-videotaped statement made by Clifton Yarborough, 17, in which Yarborough told the police he had witnessed Fuller's beating and later received $2 from one of the accused. The decision came after the videotape was reedited by prosecutors.