Addressing potential observer effects in forensic science: a perspective from a forensic scientist who uses linear sequential unmasking techniques

The linear sequential unmasking (LSU) protocol is a protocol intended to reduce the effects of potentially biasing information that may affect a forensic scientist during his/her examinations. This paper explores two central themes. The first theme is that the institution of LSU, and thus the control of information possessed by the case analyst, can affect the outcome. Some interesting case examples are offered to emphasize this point. The second theme is the exploration of the practical costs and benefits of employing an LSU approach. These issues will be explored from both the perspective of a scientist in a large, publicly-funded crime laboratory, but also from the perspective of a small, private consultant.