Janine Arvizu

Janine Arvizu testified for the defense in Steven Avery's 2007 trial about the FBI's EDTA testing of bloodstains from Teresa Halbach's RAV4. On Day 20, she reviewed the FBI report and instrument data. She said its stated detection figure described the instrument, not an established detection limit for EDTA in swabbed bloodstains. She pointed to data in which a one-microliter blood-tube sample was called positive but a two-microliter sample was not detected. In her opinion, non-detection in the three tested vehicle stains could not rule out EDTA or exclude Avery's preserved blood tube as a possible source. She did not say the tube was their source, and she had not tested the samples herself.

On cross-examination, Arvizu agreed that the FBI's qualitative method was valid and that EDTA had not been detected in the three tested RAV4 stains. She also acknowledged that she had not personally used the combined instrument system or tested blood for EDTA. She maintained that those concessions did not establish what concentration the method could detect in a swabbed stain. On redirect, she explained that results can vary near a detection limit: a positive result can establish EDTA's presence, but a non-detection near that limit cannot establish its absence.

Recross turned to the preserved tube. Arvizu said its expiration date did not show that the EDTA had broken down and agreed that EDTA was still acting as an anticoagulant in the liquid blood. On further redirect, she clarified that the tube's purple top implied EDTA was present and maintained that the FBI report could not rule out her position concerning the vehicle stains. After her testimony, the court admitted two exhibits related to her examination without objection.