While criminals rarely try to conceal shoe or tire impressions, a hasty or disorganized search of the crime scene often overlooks or destroys this evidence. To locate impressions not easily seen under normal lighting conditions, investigators should turn off all lighting and direct a strong beam from a low angle across the area being searched. Once located, all shoe and tire impressions should be photographed from directly overhead at a distance of 2 to 3 feet. Then, casts should always be made of three-dimensional impressions such as those found in soil, mud, sand, and snow. After placing a form around the impression, class 1 dental stone or plaster of paris can be used to make the cast. The article provides detailed instructions for making casts with both materials and discusses the use of a new product called snow print wax. Hard surface or two-dimensional impressions fall into two categories: dust impressions and residue impressions. Dust impressions should be photographed with an oblique lighting technique and then lifted by using a commercially available footprint lift. Many residue impressions will not transfer back off of the surface with sufficient detail, and thus each item containing the impression should be preserved and submitted to the laboratory. The article gives instructions for submitting impression evidence to the FBI laboratory and describes types of information that can be obtained from impressions, such as identifying the type of shoe or make of tire. Photographs are included.