Day 125 centered on the bloodstained socks. Defense bloodstain expert Professor Herbert MacDonell testified that blood transferred through sock 13-a without a foot inside and that the stain was consistent with blood being dabbed onto the sock while flat. Prosecutor Marcia Clark challenged his methodology, qualifications, and the discrepancy between his report's description of a 'swipe' and his testimony describing a 'compression.' Later, Johnnie Cochran represented that the Laura Hart McKinney tapes contained recordings of Mark Fuhrman using racial slurs and discussing fabricating evidence, calling the material a defense 'bombshell'; Clark disputed that characterization and said Fuhrman was furnishing fictional material for a screenplay.

• KNBC reporter Tracie Savage testified about confidential sources for the DNA leak story, invoking journalist shield law protections
• Defense expert Professor Herbert MacDonell testified that blood transferred through sock 13-a without a foot inside and that the stain was consistent with blood being dabbed onto the sock while it lay flat, supporting the defense's planted-evidence theory
• Prosecutor Marcia Clark cross-examined MacDonell, exposing discrepancies between his written report describing the stain as a 'swipe' and trial testimony calling it a 'compression'
• Johnnie Cochran represented that the Laura Hart McKinney tapes contained recordings of Mark Fuhrman using racial slurs and discussing fabricating evidence, calling them a defense 'bombshell'; Marcia Clark disputed that characterization and said Fuhrman was furnishing fictional screenplay material
• Judge Ito allowed Thano Peratis's prior testimony on blood draws to be admitted despite prosecution objections about foundation
• Defense moved for sanctions against Clark for incorrectly telling the jury that the prosecution had not received MacDonell's notes from the April 2 sock examination; Clark denied bad faith, and Ito took sanctions under advisement