What are 'impressions' that are studied in CSI?

What are 'impressions' that are studied in CSI?

Richard Saferstein (Former Chief Forensic Scientist) gives expert video advice on: What are 'impressions' that are studied in CSI?; How does the study of tool marks help in CSI?; How are tool marks collected and analyzed in CSI? and more...

There are two types of 'impressions'. There are the impressions made, for example, of footsteps in dirt. That's a three-dimensional impression. There are also the types of impressions like when a dirty shoe comes into contact with a piece of paper. That's an imprint, and that's a two-dimensional impression.