Stephen Oppler, a District Attorney's Office investigator, testified as a prosecution witness and was examined by Marcia Clark on direct and cross-examined extensively by defense attorney Peter Neufeld. Neufeld's cross-examination zeroed in on Oppler's objectivity, pressing him on his refusal to speak with the defense privately during a recess — Oppler would only answer questions under oath or with prosecutor Clark present. The exchange highlighted a recurring defense theme: that investigators aligned too closely with the prosecution, raising questions about whether evidence-gathering visits, such as one to witness Thano Peratis, should have included representation from both sides.