In this activity, learners examine fingerprints. Learners leave a hidden print on a surface and then make their own print detecting powder from graphite (found in pencils). The next phase of the activity focuses on how to isolate the fingerprints that we leave behind, and the best types of powder to use when looking for fingerprints. Extensions provided on pages 7 and 8 look at different surfaces, powders that are involved in taking fingerprints, and even catching a thief. Part of the 21-activity guide published by OMSI, No Hassle Messy Science with a Wow. All activities in this guide use household materials and all lesson plans include preparation directions, demonstrations, procedure sheets, cross-curricular connections, and scientific explanation of content.