Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: TUESDAY, June 27, 1995 TAG: 9506270078
SECTION: NATIONAL/INTERNATIONAL PAGE: C-5 EDITION: NEW RIVER VALLEY
SOURCE: Associated Press
DATELINE: LOS ANGELES LENGTH: Medium
``It was worse than I realized,'' said Bruce Weir, a world-renowned population geneticist whose statistics had been seen as a potentially dazzling capstone to the prosecution's DNA presentation.
He said he thought he had made an error in only one of his calculations but instead found the error ran through most of his totals for how many people in the population might have contributed to certain blood stains said to link Simpson to two slayings.
``Unfortunately for me, my program had a mistake,'' Weir told jurors. ``So, I was consistent, but consistently wrong.''
All of Weir's testimony involved stains that contained a mixture of blood from at least two people. His role was not to tell jurors whose blood was in the stains, only what the chances were that the blood came from any two or three given people in the world.
His mistakes, however, all involved stains that DNA experts already had said probably included Simpson's blood. For that reason, the defense contended Weir's errors were biased because they made it appear very unlikely that someone other than Simpson could have contributed to a stain.
Defense attorney Peter Neufeld led the witness through a series of corrections showing, according to his new figures, that it was now about 2 1/2 times more likely that someone other than Simpson could have contributed to mixed blood stains found in Simpson's Bronco and on a glove discovered at his estate.
For instance, three stains on the Bronco's console that were known to include the blood of two persons were originally calculated by Weir to indicate a chance of 1 in 1,400 that any two people in the population could be responsible for such stains. When Weir corrected his calculations, the chance rose to 1 in 570.
The North Carolina State University scientist, who revised his calculations over the weekend, was clearly measuring the impact on his own career.
``I woke up this morning at 5 and wondered how I could avoid embarrassing myself again in court,'' he said.
Looking at a board listing some of his original calculations, Weir said, ``All of the pairings on the board were wrong for all the profiles. I'm going to have to live with that mistake for a long time.''
Under redirect questioning by prosecutor George Clarke, Weir at first insisted he did not give special weight to the fact that some of the blood stains had been linked to Simpson and the victims.
But before he left the stand, Weir testified that his figures show ``a very rare profile'' linking blood evidence to Simpson.
``Is it just that he's not excluded or something more powerful?'' Clarke asked.
``The evidence says it's very unlikely we would see that evidentiary profile if it came from someone else,'' Weir said.
Weir's testimony was followed by the start of hair and trace evidence. Prosecutor Marcia Clark asked a police laboratory technician to tell exactly how each piece of evidence was opened, examined, packaged and, in some cases, placed in an evidence freezer.
Witness Denise Lewis said she processed hairs, fibers from Simpson's Bronco and clothing from both victims, but didn't handle bloody gloves and a ski cap collected in the case. Her testimony is expected to be followed by scientific analysis of trace evidence.
Memo: NOTE: Shorter version ran in Metro edition.