He was previously the William Neal Reynolds Professor of statistics and genetics and director of the Bioinformatics Research Center at North Carolina State University.
[4] During his testimony in the O. J. Simpson murder case, Weir was pressed by lawyer Peter Neufeld on his failure to include a certain genetic marker in his calculations of some of the DNA frequencies he had analyzed.
In response, Weir acknowledged that he had in fact made a calculation error in failing to include this marker in all of his analyses of DNA samples in the case.
Lawyers for the defense used this admission to attempt to undermine Weir's credibility, despite the fact that the error had little effect on the validity of the DNA evidence that had been presented.
Weir stated that after redoing his calculations, the odds that a blood mixture sample taken from the steering wheel of Simpson's Ford Bronco came from two unknown people increased from 1 in 59 to 1 in 26.