When it comes to impression evidence including latent prints, footwear, and tire tracks, times have changed. What forensic scientists considered acceptable testimony, or even best practice ten years ago, may no longer be acceptable. But what is it that is no longer acceptable and why has it changed? As you pour over trial transcripts, there are key terms and phrases to watch for that not only cause confusion, but may have overstated the strength of an association…and we are confident of this “to a reasonable degree of scientific certainty”. In fact, we are so confident that we have “excluded all other possibilities”. This lecture will cover testimony “with 100% certainty” that has been used by latent print, footwear, and tire track examiners in the past, why specific phrases are problematic, and what to expect from a lab report, affidavit, or expert testimony today.